Hack Your Enemy

So, you are fighting robotic enemies. Maybe it's Robot War, or your enemy just use computer controlled soldiers. Why not hack some of them? You can turn them off without a fight, or even better - reprogram them to think you are their commander and their commanders and allies are their enemies so you get free reinforcements and ideal infiltrators.

For biological alternatives see Puppeteer Parasite, Brainwashing and Mind Control. You may notice that they are much more "evil" thing to do, presumably because even ridiculously human robot lacks "soul" of some sort and therefore it is not a bad thing to completely alter his personality. Can lead to a Face Monster Turn or Apologetic Attacker.

Anime and Manga

 * Ghost in The Shell:
 * In episode "Automated Capitalism". While the team is infiltrating a millionaire's estate, Batou is pursued by robot dogs. He neutralizes them by hacking into their computer brains.
 * In the first movie, people were hacked, giving them False Memories amoungst other things.
 * In one episode The Major directly controls Togusa to stop him allowing himself to be made a scapegoat because of his Lawful Stupid nature.
 * The third movie's Big Bad is called "The Puppetmaster". Guess what he does.

Comic Books

 * Magnus, Robot Fighter Pulled this stunt at least once, by knocking the robot offline, opening up the back panel, disabling its wireless and setting it to local speech control.
 * Rai (Valiant Comics) has this as a superpower. With the cry of "MINDLOCK!" he can take control of any one machine within the range of his voice.

Film

 * In Terminator 2 and Terminator 3, the future John Connor reprogrammed a captured T-800 Terminator and sent it back in time to protect the young John Connor from a more advanced Skynet-programmed Terminator.
 * Flynn hacks a guard program in Tron Legacy.
 * Pretty indispensable in Robot.
 * Seemed very common in the Robo Cop films; it was like anyone of school age had the skills to reprogram an ED-209.

Live Action TV

 * In episode Deliverance of Stargate Universe they hacked enemy unmanned fighters to fight other fighters
 * Terminator: The Sarah Connor Chronicles. John Connor reprograms yet another Terminator (named Cameron) and sends it back in time to protect his earlier self.
 * In Get Smart Hymie the Robot was an invention of KAOS to infiltrate CONTROL, which CONTROL then reprogrammed for niceness instead of rottenness.

Video Game

 * In the multiplayer mode of Metroid Prime 2, one of the powerups you can get allows you to hack your opponent using the scan visor. This results in them taking continuous damage and a fuzzy screen for a short time (pictured above).
 * In Fallout 2 you can hack turret control to use them against final boss.
 * In Half Life 2 Alyx hacked security system in Nova Prospect and programmed turrets to shoot guards and not Gordon. Gordon himself reprograms land mines by simply grabbing them with gravity gun.
 * In Mass Effect 1, AI Hacking is an unlockable ability for an Engineer-class PC and Tali. In 2, it is also available for Legion, whose loyalty mission also involves taking control of enemy turrets and
 * In Mass Effect 3, such functionality gets wrapped into "Sabotage", which encompasses causing weapon malfunctions against organic foes as well. Becomes very useful in turning the tables on Cerberus combat engineers and their deployable turrets.
 * In Bio Shock you can hack the flying defense turrets, which then follow you around and shoot the enemy. You can hack security cameras as well, but that's another trope.
 * In Project Snowblind you can hack pretty much any robotic enemy.
 * In the original Alter AILA, Orange's special ability involves this.
 * In flash game I Am an Insane Rogue AI you play as insane rogue AI. At the beginning, hacking maintenance robots is the only way to kill inhabitants of buildings you attack. Later you will gain access to various other methods, but hacked robots and turrets will remain primary cause of fatalities.
 * Iji lets you do this to pretty much any Mook if you have enough points in "Cracking".
 * In Golden Eye Wii you can use your smart phone to hack the computer controlled guns, which will then kill any mook in their range.
 * System Shock 2 allows you to hack defense turrets if you can sneak up to them, turning them over to your side.

Western Animation

 * In one arc of Star Wars the Clone Wars, a rescue operation involved reprogramming separatists' droids to think R2-D2 is their commander.
 * In the Teen Titans series, Gadgeteer Genius Gizmo often uses this technique on Cyborg.

Real Life

 * Supposedly, one of the reasons that the United States Navy suffered no casualties during the 1986 "Line of Death" confrontation with Libya was that the American military successfully hacked and effectively disabled Libya's air defense systems.