Poke in the Third Eye

""Do you have anything you wish to say to me," he asked the air, "or shall I simply strike you blind where you sit?""

- Gromph Baenre, Condemnation by Richard Baker

It's a pretty well established fact that the Invisible Jerkass is a Jerkass. Being able to see and do things without ever possibly being detected, much less identified, gives one a dangerous sense of omnipotence. The same is true for psychics or magicians who can use a Crystal Ball, Astral Projection, precognition, empathy or Telepathy to snoop where even the CIA can't... and with no possibility of detection! They'll gather even private information with impunity, because really, what is a Muggle going to do stop him or her?

Give them a Poke In The Third Eye.

Turns out the "undetectable" Sinister Surveillance the Mad Scientist cooked up ain't so undetectable. Somehow the subject can detect Being Watched and does not take kindly to it. The voyeur will slowly be creeped out when the subject does not break eye contact with them despite supposedly being invisible, kilometers away, or centuries in the future, only to follow it up by somehow overloading the system, killing the Animal Eye Spy, or jamming the transmission. If the viewing method is mystical or psychic (or sufficiently advanced cyber implants), it can get painful for the voyeur.

The reason is that the subject has a rather painfully full bag of counter-surveillance techniques. Mystical and psychic voyeurs will be hit with the equivalent of a Brown Note beamed directly into their brain (or Crown Chakra, whichever). If that doesn't make the voyeur go comatose, it will likely at least make them faint. Especially sadistic mental traps will use Things Man Was Not Meant to Know in place of a Brown Note... because people with Power Born of Madness enjoy making oracles go mad.

Another frequent trap, usually employed by powerful villains on foolish good guys who attempt to scry their foes, is to overwhelm the seer and use Mind Control to really mess with them. This is a favorite ploy of Sealed Evil in a Can.

A possible subversion would be to not really know you are being spied on, but are spied on enough that you get suspicious and then proceed to use a defensive technique, or just stab randomly at the weak plaster walls, whichever comes first.

When the 'third eye' belongs to the audience, the 'fourth wall' is being broken.

See also I Sense a Disturbance In The Force, Psychic Static and Psychic Block Defense.

Anime & Manga

 * While he knew the person knew he was there, Natsu of Fairy Tail was able to overwhelm Cobra's ability to "hear" his thought by basically thinking really loud.
 * Nana in Elfen Lied can temporarily block other dicloniuses' vector usage with a literal Poke in the Third Eye.
 * In JoJo's Bizarre Adventure, Dio can tell whenever Joseph is using his Hermit Purple ability to observe him, though only on one occasion does he actually bother responding when it happens.
 * Darker than Black the "observatory" uses observer apparitions produced by catathonic mediums and invisible for anyone except other mediums and Contractors, to spy around. And then they ran into one Contractor who can catch these.
 * In an episode of Nightraid 1931, the protagonists face another super-powered individual who in addition to several other powers, can read minds. He's defeated by the telepath of the group falsely broadcasting a message that another's powers have run out, which he doesn't realize was a lie, since his powers don't allow him to separate unconscious thoughts to truthful sounding ones deliberately broadcast.

Comic Books
"Doc Samson: Hello. Did you really think one of the best psychiatrists in the world wouldn't be able to tell when a telepath's trying to slide in the side door?"
 * Hawley Griffin in The League of Extraordinary Gentlemen thinks that his invisibility is perfect, so much so that he is willing to even approach an invading alien army alone to have a chat with them.
 * The Invisibles has a sequence where King Mob is captured by the Conspiracy and is being tortured and mind raped by Sir Miles, who's trying to tear through the fictions King Mob makes up in his head in order to find out who he really is. Once Sir Miles starts hitting pay dirt, however, King Mob reveals he's been trained to set up mental traps for whoever fucks with his head...
 * Happens twice over in the "Black Science" arc. Mr. Quimper manages to take control of the squad leader who's got the Invisibles at gunpoint, but Robin manages to overwhelm the connection, taking control of the leader and giving Quimper a serious bout of psychic trauma.
 * A not so direct example: An issue of JLA had Martian Manhunter trying to spy on a Senate meeting as to ascertain if perhaps the current crisis in Gotham City (plagues, quakes, and a federal quarantine) had any political connections... but the second he started using his mind-reading powers, he was struck by a telepathic backlash, the result of anti-telepathy measures installed by the Department of Extraordinary Operations.
 * Klarion the Witch Boy once sensed the Martian Manhunter spying on him, and gave him a near-stroke by yanking his mind the rest of the way through.
 * In Universe X, the mysterious Ronin is aware that Nighthawk is observing him clairvoyantly (and possibily precognitively). Nighthawk has no idea how Ronin is able to do this; apparently it's a small bit of magic that Ronin  picked up over time. Ronin doesn't get to attack Nighthawk, but it's good for freaking him out.
 * The world of Transmetropolitan has so many nanites floating in the air at all times, including cameras, that it's practically impossible to go anywhere within civilization (barring the Reservations) without being detected. In one story, Spider manages to escape notice from the police with the help of an EM device that temporarily overloads the memory buffers of all ambient cameras.
 * The villains, of course, generally get around this by being the ones who are responsible for the cameras.
 * Promethea has the telepathic member of the Five Swell Guys reading Sophie's mind as she goes on a Vision Quest to learn from the previous Prometheas. As Grace leads Sophie through a Conan-inspired land scape, she realizes they're being watched. "What do you think you're doing, you pervert?"
 * A Conan the Barbarian comic Crossover with Elric of Melnibone had a literal example on the poking part. A magician is using his scrying pool to spy on the Big Bad... who senses it, and tells his Dragon to thrust her magical sword in the direction of the magician's point of view. Cue water leaping out of the pool and a lost connection.
 * In Thunderbolts 19, when a telepath tries to get into Doc Samson's head, he notices and blasts her with his gamma rage.

"Yeagar: Artax, can't you just cast some kind of telepathy spell or something? Artax: Big bad with the skull-stick would probably notice that and make my brain explode using my spell as a fuse."
 * Nodwick got into trouble. The problem is that he happens to be the one who would "usually come up with a brilliant plan".

Fan Works

 * In With Strings Attached, the Raleka wizards cover the entire dead city of Ehndris with Poison Protections. The moment Ringo tries to scry anything there, he screams and falls over, having had the equivalent of a knife in his thoughts. Worse, when the four are forced to enter the city, Ringo endures constant crippling pain, leaving him unable to do anything except stumble along holding his head.

Film

 * The Beast in Krull could detect hostile scrying attempts by the Emerald Seer and crushed his viewing emerald.
 * Pretty much the whole point of Scanners. Trying to listen in on somebody's thoughts can be very dangerous.
 * In the first X-Men movie, Mystique sabotages Cerebro to knock out Professor X next time he goes to use it. And an inversion: In X-Men 2, it's revealed that if the Professor ever concentrated TOO HARD on finding someone... THEIR head would explode!
 * Deja Vu: When first using the Snow White device to look into the past, Carlin is unnerved by Claire's apparent ability to sense that she's being watched from the future.
 * The main characters of Inception thought that the tough part of the job would be working around established theories: Namely, they needed a way to enter a character's dream-within-a-dream-within-a-dream, and once they figured out how to do so, the mission would be cakewalk. As it turns out, their target has trained his subconscious to attack dream-raiders, turning the mission into a desperate struggle for survival.
 * The movie Dungeons and Dragons: Wrath of The Dragon God, sequel to the first movie, has Damodar repel a scrying spell in a Nightmare-tastic way, complete with Large Ham Evil Gloating.
 * Happens literally in The Beast Master, when the hags scry on the heroes using the eye-symbol of an enchanted ring one is wearing. One of the heroes spots the ring opening and stabs it with a burning stick, which strikes the spying hag blind.
 * Constantine. Constantine is using The Chair to magically spy on the Mexican man possessed by the Spear of Destiny. When the man realizes he's being spied on, he somehow grabs Constantine by the throat and tries to strangle him.

Folklore

 * There's a tale involving The Fair Folk where a house maid is taken into a faerie's household and given an ointment that allows her to perceive them; however, she must wash it off when her durance is completed, otherwise she'll pay a hefty price. Thing is, she only washes it off of one eye, and is therefore able to perceive the world of the fae. At least, until she goes to market and spots one of the faeries, who realizes that the house maid can see her and decides to enact this trope -- literally.

Literature

 * There's one in David Eddings's Belgariad series. Rather scary, too.
 * In the novel Good Omens, a witch at her pyre looks up and throws a cheerful insult at the sky. Onlookers take it to be strange blasphemy, not figuring that she might be staring directly at a Witchfinder who is watching from a dream three hundred years later.
 * In the novel Pastwatch by Orson Scott Card,
 * The Hounds of Tindalos, a story by Frank Belknap Long intended as part of the Cthulhu Mythos, depicts an experiment in mental time travel that goes horribly wrong when the traveller is spotted by the title entities, spectral creatures from another plane of existence who follow him back through time and eventually kill him.
 * The Fellowship of the Ring. When Frodo sits in the seat at the top of Amon Hen while wearing the One Ring, he sees many things with the seat's scrying ability, including Sauron's dark tower. Unfortunately Sauron detects him, and sends his will to locate him. Frodo barely manages to take off the Ring in time and Sauron's attack (in the form of a black shadowy arm) misses him.
 * LotR's "fancy crystal balls" were called Palantíri, and the problem with using them was that Sauron had acquired one and could turn his will against anyone who tried using the others. Only Aragorn was strong enough (barely) to resist—and by doing so, unsettled Sauron almost as badly as Sauron had scared Pippin, who had earlier made the mistake of looking into it.
 * Isaac Asimov's Second Foundation has a mechanical version, devised to jam the mental abilities of the second foundationers; the devise generate a field of static that prevents the second foundationers from sensing (and changing) the emotions of others, however, when the you increase the intensity of the field, it becomes incredibly painful to whomever can sense emotions. The inventor calls it a "Mental Static generator".
 * Happens to Harry Dresden, in a rare villain-to-hero example, while the eponymous hero is using Little Chicago.
 * In the RPG, he notes that not only is physically harming someone through a scrying normally impossible, but the villain Cowl essentially did it through two different scryings, since Harry was himself spying on a scrying. Harry is not surprised by the fact Cowl was able to do something doubly impossible.
 * Harry does this to the Big Bad in the first Dresden Files book, Storm Front, to prove his point that Council wizards know more tricks than "independent" warlocks. And to piss him off.
 * In The Pilo Family Circus, while surveying the grounds with the stolen crystal, JJ finds that Kurt Pilo can detect his attempts at scrying, and while JJ isn't actually attacked, Kurt's mocking little wave is enough to make him stop watching.
 * The Candy Shop War (aimed towards kids 7 to 12) includes a scene where the character find out that the witch has been watching them with a floating eye disguised as a bubble. They shoot it, causing it to pop in a mess of blood. The witch only has one eye after this point. Once again, aimed towards kids 7-12
 * Stephen King's The Dark Half has a scene where Thad links his mind to George to get information. George figures out what Thad is doing and uses the link to make him stab a pencil through his hand.
 * The Larry Niven short story "The Soft Weapon" gave this method to torment Kzinti telepaths in his Known Space universe: think about eating vegetables. The Kzinti, being a race of carnivores, find this disgusting to the point of traumatization, actually refusing to read the mind of herbivores.
 * According to the Jedi Academy Trilogy, Force Sensitive people have a certain part of their brain that will reflexively do this during any attempts to probe said area, psycho-kinetically pushing the one doing the probing. The stronger the person is in The Force, the farther the one doing the probing will be hurled.
 * In Harry Potter and The Chamber of Secrets, Harry and Ron are witness to the Minister of Magic calling for Hagrid's arrest, and to Lucius Malfoy delivering an order of suspension to Dumbledore, while under the Invisibility Cloak. Dumbledore gives some sage yet cryptic advice, looking directly at the still invisible Harry and Ron, despite only Hagrid being the one seemingly aware of their presence in his hut.
 * It's somewhat surprising that this doesn't happen more often. Harry spends the fifth and seventh books periodically accessing Voldemort's mind and thus gaining valuable information. Since Voldemort is allegedly a master of legilimency (mind reading), it's strange that he never detects this and inverts it for Mind Rape.
 * Voldemort actually The seventh book is explained through Voldemort going totally batshit crazy that he doesn't even notice Harry's intrusion.
 * In The Bartimaeus Trilogy, demons who scry on a powerful sorcerer or a high-ranking demon run the risk of discovery and...retribution.
 * In Green Rider, Karigan views Captain Immerez through the telescope at Seven Chimneys, through a large distance (and if this troper recalls correctly, time). He proceeds to look up, speak to her, and try to gouge out her eye with his hook-hand.

Live-Action TV
"Hello, Delvian. 10th-level Pa'u? Pity. 12th could break this bond. Time to pray."
 * In Heroes, Matt and Mohinder have Molly use her power of Clairvoyance to locate Matt's father, Maury Parkman. In return, Maury uses his power to basically put Molly in a coma.
 * Lyta Alexander from Babylon 5 loves to do this. In one scene, she creeps out the rest of the cast by directly looking into the camera that they were using to watch her. When they switched cameras, so did she. In an another scene, Bester and other PSI cops are confronting her and she retaliates with telekinetically slapping them. Bester tries to call her bluff. She blusters and says that she really doesn't know what she's doing, and might "accidentally" kill someone by popping a blood vessel in their brain.
 * The Shadows have their own anti-PSI defenses as well,.
 * In the second season finale of Farscape, the Scorpius neural clone in Crichton's brain does this to Zhaan when she attempts to connect with his mind. After baiting her into it, no less.

"Castiel: It can be... overwhelming to humans."
 * In the Supernatural episode "Lazarus Rising", Pamela attempts to find the being that raised Dean from Hell. Unfortunately for her, Castiel is an angel. Seeing his true form ends in Eye Scream for Pamela.


 * Stargate Atlantis has Teyla, who can enter Wraith minds, and as her powers increase, even control their bodies. The catch? It's a two-way connection with an inherently telepathic alien on the other end.
 * In Buffy the Vampire Slayer, the First Evil briefly possesses Willow when she tries to scry it.

Tabletop RPGs

 * Call of Cthulhu (tabletop game). The spell Create Scrying Window enchants a glass window to allow viewing of the past. If the window is used to observe a creature able to cast spells, the creature can cast a spell that takes effect on the viewer's side of the window (in the future).
 * Early editions of Dungeons & Dragons.
 * A creature being watched by a Crystal Ball had a chance to detect the observation. If a Dispel Magic spell was cast on the viewport, Crystal Ball is rendered non-functioning for an entire day.
 * Any being that tried to use a Crystal Hypnosis Ball would have its mind influenced by the Ball's true owner. Probably inspired by the Lord of the Rings Palantir.
 * Some D&D scrying spells has a chance of the scryer being detected (in earlier editions some also had the vulnerability that certain spells could affect a scrier... Which could be taken advantage of, for eg. Mind Control)
 * "Live My Nightmare," a Spelltouched feat in Third Edition's Unearthed Arcana book of variant rules, allows a character who survived (or was revived from) a Phantasmal Killer spell to unleash a Phantasmal Killer attack born of their very worst nightmares upon anyone trying to pry into their mind by magic or other means.
 * The purest form is the spell "Terminate Scrying", closing links with backlash which causes direct damage to curious spellcasters and explodes offending crystal balls, introduced in relatively obscure Sourcebook College of Wizardry. After all, scrying spells seem to be safe when work properly, but they all use at least as much power as a fireball, some of them more.
 * Forgotten Realms novels popularized this practice. Though usually it happens when secondary functions (such as communication) are used. In The Making of a Mage an elf given an enemy spy's crystal ball claimed "Properly used, it can burn out one magelord's mind". Archmage of Menzoberranzan Gromph threatened those spying on him with blindness (see the page quote). It's rooted well enough that Counselors and Kings had a subversion: the wizard who fell for this ends up merely dazed instead of blindly flailing through his room, burned and bleeding from a dozen of shrapnel wounds.
 * Forgotten Realms sources also mention (but not give write-ups for) various traps against Mind Probes, that can be more or less damaging to the diviner and possibly the subject, which isn't always a flaw - knowing that there's a possibility that a probed noble suddenly goes catatonic (leaving the wizard who was around and messing with spell components to try and fast-talk his way out of this) is a deterrent in itself.
 * Mind-reading a Daelkyr from the Eberron campaign setting renders anyone doing so permanently insane.
 * To preserve suspense in the Ravenloft D&D setting, the rules for surveillance-spells are modified so that they create a visible, ghostly eye (viewing spells) or ear (listening spells) at the location being spied upon. Anyone who takes the time to watch out for such manifestations can thus detect when they're being observed via magic.
 * Mind-reading some of the nastier Ravenloft creatures - aberrations, darklords, the insane - can provoke a Madness check.
 * The Remote View Trap psionic power shoots lightning back through scrying abilities, and there are several powers and class features that do nasty things to the users of Telepathy powers.
 * There are several magic items and spells designed for people who enjoy their privacy. Some merely hinder attempts to scry on the wielder. Others alert the user to scrying spells used on him. Some make a stronger point by dealing significant damage to anyone scrying on the user. One in particular allows the user to express his displeasure more personally - by teleporting directly to the location of the voyeur.
 * Arcane Lore from Dragon #221 (and Wizard's Spell Compendium after it) offered Zala's Amberhelm spell, which blocks mind control in both directions and can be breached by psionic attacks with some effort, but causes damage to the attacker on collapse.
 * In a Shadowrun campaign, the wizard can leave his body to scout a source of dangerous magical energies. He finds the small and cozy house of a passionate cat owner. All the cats are staring at him.
 * In Mage: The Awakening, if a mage is being scryed (or having any form of sympathetic magic cast at him) and is able to detect it, than he can cast spells back through the connection, even if he normally wouldn't be able to cast sympathetically.
 * GURPS Magic contains a few spells that counter invasions of privacy, including magical ones.

Theater

 * Gone in Sixty Seconds - Theatre Quest Entries, a sixty-second play on Everything2.

Video Games

 * There is at least one seer in Baldur's Gate and its sequel who you can consult about your future and the seer will be noticed by someone in the vision.
 * In Baldur's Gate 2, when the protagonist and the rest of his/her party reaches Spellhold, a resident Cowled Wizard takes the group on a brief tour, introducing them to Mages who have been driven mad through incautious use of their abilities. One Mage tried to scry beyond the known planes of the Forgotten Realms, only to be given a Poke in the Third Eye by whatever lives there. The Guide chillingly lampshades this, saying "Apparently whatever he saw didn't like him looking".
 * A seer in Trademeet will offer to read you and your companions' fortunes. The companions' fortunes are fairly interesting and hint at their personal quests, possible epilogues, . Trying to read your future traumatizes the poor woman so badly that she won't read anyone else's fortunes for the rest of the game. Of course, you are carrying a rather powerful piece of Murder god inside yourself.
 * Played with slightly in the obscure game Falling Stars. When your party consults a seer in regards to the Big Bad, she starts rattling something off. The BBEG notices her probing and kills her from halfway across the world to keep her from saying too much.
 * A major quest in Neverwinter Nights: Hordes of the Underdark is centered around the results of some queen trying to spy on an archmage. In this case, he poked her with a big enough stick to.
 * In World of Warcraft, Cho'Gall does this to you.
 * In the Chzo Mythos, the druid Cabadath attempts to summon a pain elemental, Chzo, to the world. Chzo, who has devoured every other pain elemental in existence, is more powerful than Cabadath expects when the portal is opened and is not amused by Cabadath's attempts to control him.
 * The Pokémon Ruby and Sapphire pokedex entries for Xatu state that it is silent and unmoving because it is so horrified by its visions of the future.
 * In Golden Sun: Dark Dawn, one of the Fortune Teller sisters in Harapa offers you a free reading, only to have a vision of you bringing disaster upon Weyard, after which she refuses to even look at you.
 * is such an assault on little Himi's clairvoyant/precognitive abilities that it puts her into a coma. Talking to some of the Yamatai NPCs while she's still out of it reveals that her similarly-gifted aunt, Lady Uzume, had the same situation after predicting the tidal wave that washed away Izumo—she was able to warn and evacuate her people, but fell into a coma and eventually died.
 * In the earlier Golden Sun games, there are some milder forms of the trope, mainly where it concerns other Adepts. In The Lost Age, trying to Mind Read Alex will result in him either telling you to cut it out without letting you know anything, or thinking a rebuff instead of any real thoughts. There's only one place in the entire game where you can actually mind-read him. When you first run into Karst, an attempt to Mind Read her has her smile at you and threaten you in her thoughts for attempting it.
 * In one cutscene in Vagrant Story, Romeo slaps Samantha across the face when he realises Ashley is scrying on her. When Ashley recovers from his vision, he has the same stream of blood flowing from his mouth Samantha had after taking the blow.
 * In Sam and Max Freelance Police episode 304, it's a very bad idea to try to read the mind or future of.

Webcomics

 * In the webcomic Dominic Deegan, this happens occasionally. The first instance was when the title Seer scries upon a conspiracy of murderers with its own Seer. A "Seer Glyph" detonates his crystal ball, throws him back and alerts the target. Other times, it's a matter of one Seer peering at something or someone powerful enough to launch their own psychic attack at him.
 * Normally, in Gunnerkrigg Court, blinker stone spying can't be detected by humans, but Renard/Reynardine warned Annie that it's not a good idea. Jack, notices her ethereal presence, although not enough to tell it was her specifically, and he didn't attack, but she's freaked out enough to pull the plug immediately anyways. The next time she used this to get a good look at, she was trapped and attacked.
 * In the Ciem Webcomic Series, Kimiyato just loved inducing Mind Rape on Candi For the Evulz. But somehow, she couldn't detect Angie's presence. Yet...in another twist, Angie was able to sever the psychic link by being born. Its effect on Kimi was like someone sending a humongous "F-YOU!" to her psychic "chat room," then demolishing the wireless tower. The resulting Villainous Breakdown causes Kimi to go on a Roaring Rampage of Revenge in the third story.
 * Averted in the books, where Kimi is merely hunting Candi for sport.
 * In Homestuck, part of a normal session of Sburb involves an Exile contacting one of the players from the future, and helping to guide their actions. However, Sollux has had bad experiences with people doing things in his mind, so he flips out and blows up the Exile's monitor with his Psychic Powers.
 * Once Jade enters the Medium,  notices an exile is trying to talk to her.
 * A mundane equivalent happens in this Xkcd strip.

Web Originals

 * Apparently not so uncommon in the Whateley Universe. For example, even as a freshman fairly new to the school, ki mistress Chaka once tricked the infamous 'Don' Sebastiano into allowing himself to be found out trying to use his mind control on her by first closing her relevant chakra to stop his attempt and then distracting him enough that he completely forgot to drop the link as he would otherwise have—cue detention. Ironically, she didn't plan the second part. And Eldritch is not just certifiably crazy, but has deliberately turned her mind into a kind of psychic 'minefield' for snooping telepaths to run into and experience some of the unpleasant parts of her former life as a marine firsthand...
 * And Phase has now figured out a way to do this. She drove off the most powerful psychic on campus. By concentrating on a Britney Spears song until said psychic begged her to stop.
 * SCP Foundation-096 has a version of this—It knows when someone has seen its face, be it directly, in a photograph, through surveillance, or other recordings, regardless of whether they're aware they've seen it. Any time someone sees its face, it pinpoints their exact location, hunts them down, and kills and [DATA EXPUNGED] them.
 * Chakona Space has a very good example in Tales of the Folly ch. 7. Neal Foster burns Windsong's tail. Later, Quickdash threatens worse if Windsong doesn't get out of hir head.

Western Animation

 * Happens so many times to J'onn J'onz that he may as well not ever bother using his telepathy. In a bit of an inversion in JLU, Gorilla Grodd had placed telepathic safeguards in each member of the Legion of Doom that prevents them from having their minds read... unfortunately, the "safeguard" is shorting out the villains' synapses!
 * Two simultaneous attempts by villains and heroes results in a Body Switch between Lex Luthor and The Flash. Hilarity Ensues.
 * On the American Dragon: Jake Long episode "Supernatural Tuesday" the ogre gladiator Maximinus has a helmet that allows him to hear his opponent's thoughts and thus counter his fighting moves; Jake bests him
 * In the 'Venture Bros'' episode "The Doctor Is Sin", Doctor Orpheus attempts to probe the mind of Doctor Killinger, only to for it to backfire on him, causing him to suddenly faint and suffer an explosive nosebleed. It's left open-ended whether or not if Killinger is simply immune to psychic probing, or if Orpheus accidentally discovered something that even his mystical mind could not fathom.