Disproportionate Retribution / Professional Wrestling
During a match between Chris Benoit and Mark Henry, Chris managed to lock the Crippler Crossface on the big guy. After Mark escaped from the hold, he proceeded to pummel Chris, then lock him in a camel clutch, while at the same time, choking him with the ring rope. He got disqualified for using the rope, but he refused to break the hold, even after Benoit gave Blood from the Mouth. When the referee and security finally got Mark off him, Mark was screaming, "He hurt me! He hurt me!" I know the Crippler Crossface hurts, but Jesus Christ.
Happens again when Sheamus beats him. Despite being furious that no one had been able to put up a good fight against him, the fact that Sheamus actually defeated him sends Henry into a berserk rage. He pretty much tries to maim Sheamus (though due to Sheamus still having a lot of fight left in him, he fails).
Chris Jericho received some pretty violent beatdowns from newcomer Fandango in early 2013 for his mockery of the latter's name (something he tends to be a stickler about, even insisting on correcting people after he's taken a beating). This went onto spark a match at WrestleMania, which Jericho actually ended up losing.
And we can't forget the late 2000 feud between Kane and Chris Jericho which was basically two months of Kane beating the piss out of Jericho at every single turn. Why? Because Jericho accidentally spilled coffee on Kane at the catering table.
To be fair, Jericho did then make a snarky comment about hoping Kane wasn't burned. Given Kane's history, well... And Disproportionate Retribution was always sorta Kane's schtick
That's nothing compared to veteran manager "Playboy" Gary Hart (no relation to the former U.S. Senator) sending Homicide and Low Ki to attack Terry Funk at Major League Wrestling's Reloaded Tour 2004, January 10, 2004, out of revenge for Funk having lost the "I Quit" match to Ric Flair at NWA Clash of the Champions IX, on November 15, 1989.
In a later October 2006 episode of Raw, Maria accidentally spilled coffee on Eric Bischoff's shirt. His response: You will wrestle Umaga or you will be fired. Needless to say, Maria was seriously injured, and the only thing that saved her from being the hottest woman ever to be laid to rest in her hometown's cemetery was John Cena running in to run Umaga off.
This actually happened about a year earlier when Maria just asked an innocent question to a seething Bischoff who ordered her to be in a match with Kurt Angle. She got hit with a brutal Angle Slam before, once again, John Cena came to save the day. It should also mention that Eric had more than enough reasons to get Maria some payback: she pretty much chewed him out over his control over Raw in a way that no one expected: using a very extensive vocabulary and pretty much stated "Bischoff's been causing chaos in RAW and he should be fired."
Maven. The Undertaker. Royal Rumble 2002. Seriously, I understand Taker being pissed at being eliminated in the RR by a dropkick from behind, but that was largely his fault for not paying attention, and it REALLY didn't warrant the horrifying beatdown he spent the next twenty minutes doling out on poor Maven's sorry carcass, including plowing him headfirst through a popcorn machine's glass.
Which was DR in itself; the night prior (SummerSlam 2004), Orton faced then WWE World Heavyweight ChampionChris Benoit in a title match, and won. You'd think HHH would be proud of him. The problem? Orton's victory had derailed HHH's big plan, which was for Orton to soften the champ up so that Triple H could swoop in, finish off a weakened Benoit, and take the title for himself. So what does HHH do? He tricks Orton into celebrating in the middle of the ring, only to turn on him and subject him to a brutal 3-on-1 beatdown before kicking him out of Evolution and, a few weeks later, taking the title anyway.
Lesson of the story: Triple H and Randy Orton are not good people, and if you cross them in any way, they will give you hell. Just ask them. About themselves, or each other.
Razor Ramon used to exact brutal vengeance whenever someone broke his toothpick.
Early in his 1985 WWF run, to help get him over as a dirty, foul-mouthed heel with an itchy trigger-finger temper, Terry Funk beat up ring announcer/attendant Mel Phillips, bruising his ribs and tearing all his clothes off. Phillips' crime: putting on Funk's cowboy hat as he collected it before Funk's match; his hands were full with Funk's other gear.
The October 10, 2006 episode of WWE's ECW show featured an "Extreme Strip Poker" competition involving a mix of Divas from WWE Raw, WWE Smackdown and ECW. After each girl is in their underwear (and one is topless but using Hand or Object Underwear), Candice Michelle loses a match. She looks like she is about to go topless but she stops. Maria then asks if she is embarrassed. And, just for that one comment, she is stripped completely naked on national TV by the first who claimed she "cheated".
Right before stripping Maria, Candice mocked her for her inane Non Sequitur "I love ponies!" when the other Divas had been verbally drooling over John Cena and Batista earlier on the show.
The ROH "Ring Of Homicide" angle, where the titular Homicide when on a quest of revenge, which mostly involved stabbing with a fork everyone who so much as annoyed him.
In 2015, James Storm asked Mickie James, who had announced her retirement to raise her son, not to retire and to join his stable. When she declined, he threw her into the path of a train (it was a storyline, she was of course not really hurt).
This is, of course, an important part of Professional Wrestling, with the Heels often giving out brutal punishment after losing a match.