Noisy Shut Up

A bunch of people are babbling or arguing all at once. This often happens in some sort of crisis situation, especially when most of the people involved are just civilians and they don't know how else to react. Unfortunately, all their noisy anger/panic/confusion etc. is preventing any real conversation or coordination. (Moreover, it's preventing the audience from actually listening to any particular line of dialogue) Somebody needs to take charge and act like a leader. The leader may start by simply talking to people, but he finds that no one can really hear him. In any case, he decides to make a really loud noise to make everybody else shut up. This may involve a loud "SHUT UP!", or it may involve some other way of making noise, such as firing a gun into the air.

This is surprisingly effective. It's very rare for the babbling crowd to ignore the leader or tell him to shut up in return.

Related to Big "Shut Up!", but differs because it only applies when the intention is to shut up a noisy crowd, and it involves non-vocal ways of doing so.

Film

 * A great example in Kung Fu Hustle.
 * In Guilty By Suspicion (a film about the Red Scare), at the top of the film we're at a party with lots of people chattering, and one gets everyone's attention by saying "Ladies and gentlemen...Ladies and Gentlemen!....COMRADES! That got your attention, huh?" Note that it wasn't a communist meeting, just a get-together, but it was later cited as a communist meeting during the protagonit's trial.
 * Kindergarten Cop had Arnold Schwartzenegger's character do that to a kindergarten class. They shut up all right... then they start crying.
 * Ginny does this in Harry Potter and The Half Blood Prince film.
 * This happens several times in Muppet films.
 * In The Great Muppet Caper, Kermit tries to call the meeting of him and the Happiness Hotel's gang to order with a loud, "QUIET!" upon which everyone stops talking...except for Janice. "...So I said, 'Look, mother, it's my life, okay? So if I want to live on the beach and walk around naked- oh." The second time is when everyone is making excuses to not go stop the crooks, Fozzie shouts them down so he can make a Rousing Speech.
 * In The Muppet Christmas Carol, Fozzie, as Fezziwig, tries to get everyone's attention at his Christmas party, Animal bellows, "QUIET!" After the noise stops, he mutters, "Thank you..."

Live Action TV

 * The Doctor Who episodes "Midnight" and "Planet of the Dead", along with a bunch of other episodes.

Manga & Anime

 * Angel Beats! episode 5: Between exams, the SSS argue about the methods they're using to sabotage Angel's exam results. Three times this happens, and three times this ends with Yuri screaming at them to shut up and slamming on her desk (followed by a hasty explanation from Otonashi to Angel about why they're being so loud).
 * Germany does this to the other nations in the first Axis Powers Hetalia episode.

Radio

 * The Navy Lark a bickering meeting of Mad Brass is brought to silence by the shout of "SHUT UP or I'll lock up the Gin".

Western Animation

 * In an episode of Powerpuff Girls, Fuzzy Lumpkins yells this... and gets elected mayor because of it.
 * An interesting variation occurs in Adventure Time. After Peppermint Butler gets a drop of VERY spicy serum in his eye, he's screaming loudly in pain. Lemongrab (who has No Indoor Voice) screams at the top of his lungs: "STOP SCREAMING!!! WHY ARE YOU SCREAMING?!"