This is played with in Axis Powers Hetalia. Canada is frequently the target of this because he looks almost identical to his brother America, though the countries that are pissed at America wouldn't harm Canada if they knew the difference. That he's very soft spoken means he rarely is able to stop the abuse or convince the other countries (rightfully angry at America) from beating up on him.
A particularly bad example in the case of the anime-exclusive villain Valgaav from Slayers; he was subservient to Gaav, one of the world's five Dark Lords, and he goes on an all-out vendetta against Lina and her comrades for killing him. Problem? Another Dark Lord, Phibrizo, killed Gaav, whereas it took a massive effort for Lina and co. to stand against him.
Zuuma from Revolution and Evolution-R is even worse. His reason for wanting to kill Lina is because she killed the group of bandits who killed his wife.
To elaborate: His brother was ordered to kill his entire family to save his village from civil war and prevent a world war that would've killed thousands of innocents all over the continent. Only the three village elders even knew about that. After he found out about that, Sasuke promptly decided to massacre every man, woman and child in the village, including dozens of people who used to be his friends/family substitutes/ mentors, in other words, genocide, just because they owe their lives to what was done to him, who cares if many of them value and love him way more than he ever deserved, or if they weren't born yet when it happened? Needless to say, neither his allies nor random innocents who are just doing their job are safe anymore.
In Mai Hime, Nao, who has turned fully antagonistic after losing one of her eyes in a fight with Natsuki (which, unbeknownst to either, was the result of manipulation by Nao's alleged victim Yukariko), decides to seek revenge on everyone whom she blames for this. This, unfortunately, includes Mai, who tried to stop the fight between Nao and Natsuki, and Natsuki decides to take revenge on Mai by targeting Takumi instead. To a degree, this can also apply to Shiho's grudge against Mai (for which she kills Takumi by destroying Akira's Child), since it was Yuuichi's declaration of love for Mai that showed her that he was attracted to her, rather than anything Mai did, although it also falls under Murder the Hypotenuse in that Shiho wants Mai out of the way as long as she is a potential rival.
In One Piece, Duval targets Sanji, who has never met him before, because the poorly drawn composite illustration of him happens to look like him, resulting in Duval being attacked by Marines and bounty hunters who are looking for Sanji (interestingly enough, not over the crimes Duval actually committed).
In Murasakiiro No Qualia, Hatou toward Alice in consequence of Yukari's death. Alice never meant for it to happen. Quite the opposite, she truly believed JAUNT would be able to protect Yukari.
One of Green Lantern's Silver Age antagonists was the Aerialist, who was under the delusion that someone at Ferris Aircraft had murdered his beloved (her death was in fact a freak accident) and therefore sought revenge against the company. Notable for being one of the few times Hal Jordan thought the Insanity Defense would actually work, even citing the M'Naughten guideline.
In The Trial Of Superman storyline, Superman is sentenced to death by an alien tribunal... because one of his ancestors had perfected a device that made it so that most of the Kryptonians couldn't leave their planet without dying, which meant they couldn't leave when the planet blew up. The fact that Superman was only a baby when this happened was ignored by the judges: all that mattered to them was that Superman was related to a killer, therefore he would have to pay for the crime.
There is the origin of Doctor Doom. When they were in university, Reed Richards spied Doom's notes for his grand experiment and tried to warn him that some of his calculations are off, which threatened disaster. Doom refused to listen and when the experiment blew up in his face as Reed warned, Doom could not accept that he made a mistake and irrationally accused Reed of sabotage, starting their lifelong enmity.
In Sonic the Hedgehog, Thrash the Devil, like the other dwindling Mobian-type Tasmanian Devils, had been told that the echidnas were evil due to the fact that, centuries ago, a group of scientists modified them, turning them into Devil Dogs slowly over the years. Thrash ended up getting his revenge, leading to the last leader of the Devils to make a realization that what she had told had Gone Horribly Wrong: Thrash had sent every last echidna outside of Knuckles himself into another dimension out of spite.
In Nightwing, it is revealed that, once a generation, the Court of Owls takes a single child from Haley's Circus to become one of their Talons every time the circus visits Gotham City. This child would then be tortured, trained and experimented on. Dick Grayson himself was supposed to become a Talon, but of course, his parents are killed and he is adopted by Bruce Wayne. So instead, his friend Raymond is taken, but washes out and has his eyes pecked out. Years later, Raymond returns as Saiko and claims that Dick Grayson is the worst killer evargh and tries to kill him, along with everyone else in the circus at the time. Except: 1. Dick couldn't have possibly known about this (Batman himself didn't know about the mere existence of the Court of Owls, let alone their methods) 2. Dick was in mourning and had found a kindred spirit who could help him achieve his goals (good old vigilante justice) 3. Dick didn't kill him 4. The audience has nothing to do with this.
In The Lion King Adventures, Mtumwa tries to kill Simba (and Nala by extension) for Scar's death, even though that was actually Hago's doing. This is actually justified, however, as Mtumwa wasn't present when it happened, and only heard about it after it was distorted by word of mouth retellings.
This is Two-Face's deal in The Dark Knight. Rather than The Joker who actually orchestrated his tragedy, he goes after everyone who was involved in the events, no matter how weakly or by how many degrees of separation, even to the point of threatening Gordon's son (so Gordon will understand what it's like to lose the person he loves most). He reasons that the Joker was "a mad dog" and he's going after the ones who let him off the leash and the people who failed in their job to stop him before the tragedy.
In Star Trek: Nemesis, Shinzon directs his hatred of the Romulans towards Earth for reasons which only make sense to the screenwriter. It's never even explained what bizarre line of reasoning led to him wanting to destroy Earth and not, you know, Romulus. It's implied to be motivated by a particularly mean spirited variation of Cloning Blues but it still doesn't make much sense.
In Hellraiser Hellworld, The Host reveals that he's torturing the protagonists because he blames them for his "beloved" son's suicide. Chelsea points out that this makes absolutely no sense because they were his best friends who loved him dearly and did everything they could to help him. Plus, The Host is a hypocrite because he walked out on his family over 16 years ago and didn't even attend his son's funeral, so he has no right to claim he cares about his son. The Host ignores this and continues the torment.
Nine Dead: The Kidnapper wants revenge against his nine captives for the role they played in the death of his son. These include the man who raped him thus giving him AIDS and the lawyer who framed him for a liquor store robbery. Also includes the guy who was owed money by the REAL robber, and a priest who heard the Confession of the robber.
Law Abiding Citizen has Clyde Shelton retaliate against anyone who even remotely related to a deal the prosecutor made with his family's killers (the accomplice got the needle, while the actual killer was released)... except the prosecutor himself. Basically, his rage is against the US legal system, so anyone is fair game.
Star Trek has Nero, who might be the craziest example on this page. When Spock fails to save his homeworld Romulus (including Nero's family) from a horrible natural disaster, Nero goes completely nuts and goes back in time to wipe out the entire Federation. He goes for Vulcan first since it's Spock's "fault" that Romulus is gone. Spock really tried his best to save Romulus, which in itself is amazing given the Romulans' less than pleasant history with the Federation (especially the Vulcans). Nero wants to wipe out the past, present, and future of Spock and everyone Spock loves anyway.
Live Action TV
Cold Case: A young boy is horribly abused in a group home. So when he grows up, does he track down those who abused him and those who let it happen? No. Instead, he selects completely innocent boys who bear only the vaguest resemblance to his former tormentors and kills them, putting them through the same abuse he suffered.
Grange Hill: In a mid 90's episode, a guy and a girl try to escape from a fire by climbing out of a window. She slips, falls to her death, her boyfriend blames the guy who was with her and spends the rest of the season stalking and harassing him. He eventually stops and apologizes (possibly since everyone was against his vendetta).
Law & Order: UK: Matt Devlin is killed in a drive-by by a young man looking for revenge on the police for botching the murder investigation of his brother, a screw-up he believed was racially-motivated. Problem is, not only was Matt, not a bigot, he had nothing to do with the case (and probably would've been steaming mad about it). What's worse, the killer had an idea of actually pulled the trigger (a local drug dealer who may have been lying to gain street cred)—why not go after him or one of the cops who DID botch the case?
Jack McCoy's zealous prosecution of a drunk driver who killed three people. Reprehensible, certainly, and fully deserving of a harsh prison term. But it soon becomes obvious that his actions are motivated by the fact that the drunk driver who killed his lover Clare received a light sentence.
In the episode that was the basis for the Law & Order: UK episode cited above, except that here, the perp was much younger (14) and the victim survived with only an injured arm.
Merlin: King Odin tries to kill Arthur (twice!) because Arthur bested his son in a Duel to the Death. As Arthur tells it, the young, inexperienced prince challenged Arthur and Arthur could not refuse due to the knights' code. Arthur even (unsuccessfully, obviously) tried to convince the boy to withdraw his challenge.
"No Quarter" has Private Richards beat up Danny Matheson over the death of his best friend Templeton back in "Pilot". It's true that Danny pulled a crossbow on Templeton, but Templeton shot first. It's true that Danny shot Templeton with his crossbow, but one of the villagers named Caleb shot and killed Templeton. Clearly, Richards is after people who are indirectly responsible for the death.
"The Longest Day" has Rachel Matheson reveal that she only wants to turn the power back on so the other factions will kill Sebastian Monroe, and she'll get her revenge for her son's death back in "The Stand". Earlier, Rachel tries to kill Major Tom Neville over her son's death, and had to be talked out of it by Charlie Matheson in "The Song Remains the Same". Rachel tries to go into Monroe's tent and blow them up with a live grenade in "Clue". "Children of Men" had Monroe himself say that he wasn't even there when she reveals why she's out to kill him. The thing is he's right, because one of Monroe's helicopters was firing wildly and Danny got caught in the crossfire. It wasn't like Monroe killed Danny personally.
Star Trek: The Next Generation: The episode "The Survivors", where members of an alien race kill a powerful being's wife. In retaliation, he kills the entire race, all fifty billion of them. He acted in a moment of rage and was horrified by what he'd done.
Buffy the Vampire Slayer: In season 6. After skinning Warren alive out of revenge for his Accidental Murder of Tara, Willow proceeds to target his accomplices Jonathan and Andrew, who were both in jail at the time and had nothing to do with it. Though the Scoobies (sans Buffy) all rallied behind Willow en masse when she targeted Warren, they all agreed that Jonathan and Andrew don't deserve to die at all and work together to protect them.
In Harry Potter, Severus Snape's hatred for James Potter, his childhood bully, quickly transferred itself onto his son Harry once he started Hogwarts, causing him to be stricter towards him then any other student. The last book however reveals that the real reason has more to do with Snape being hopelessly in love with Harry's mother, Lily Evans, making Harry a constant reminder that the love of his life, had ultimately married the man he loathed most of all.
In Diane Duane's novel Spock's World, the Big Bad's motive is revenge on Spock for a death in the family...except that an outsider would probably say it's not his fault at all.
In The Breaker, a great deal of characters are after Han Chun Wo, also known as Goomoonryong, because he killed their master or performed some other dishonorable thing upon their martial arts school. He is a complete and utter Badass upon which they have no hope of carrying out their revenge. Therefore, they prefer to target his student, Yi Shioon, which becomes particularly unfair and messed up in The Breaker: New Waves when Shioon looses his ability to use ki and becomes completely helpless, is renounced by his Master as a student and is no longer a Murim (part of the martial arts world) and should be off limits.
Backfires pretty horribly on them since his Master actually started a process that would make Yi Shioon even stronger in Shioon's body (his ki center being broken was a necessary first step). After the first hundred chapters or so, they are seeing Shioon as a threat in his own right.
Religion, folklore and mythology
This was endemic among the Greek gods. "Zeus seduces/rapes some mortal woman, then his wife afflicts that woman and/or her son with a curse as punishment" is a fairly typical plot outline, and the other gods weren't much better.
Julius Caesar: In real life, after the murder of Julius Caesar, the poet Helvius Cinna was killed by a vengeful mob because he was mistaken for Cornelius Cinna, one of Caesar's killers. In William Shakespeare's dramatization of the event, Helvius is killed because his name is Cinna, despite his protests that he had nothing to do with the assassination.
Cinna: Truly, my name is Cinna.
1st Citizen: Tear him to pieces, he's a conspirator.
Cinna: I am Cinna the poet, I am Cinna the poet.
4th Citizen: Tear him for his bad verses, tear him for his bad verses.
Cinna: I am not Cinna the conspirator.
4th Citizen: It is no matter, his name's Cinna. Pluck but his name out of his heart, and turn him going.
In Ar Tonelico 2, Luca for the longest time holds Lady Cloche responsible for the death of her younger sister. Cloche could not realistically have been responsible for that, considering she was only six or seven years old at the time and even though she's the head of state now, she has always been a puppet ruler who never made any real decisions. And even more so because Lady Cloche IS Luca's sister.
In the Ace Attorney series, any time Franziska gets offended by someone she cannot whip, she immediately whips someone nearby, often Phoenix, Edgeworth or Gumshoe. In a more serious sense, this is Godot's entire motivation; He gets poisoned by Dahlia Hawthorne, and when he wakes up, Mia Fey, the woman he loved, is dead and Dahlia is on death row. Feeling as though he failed to protect her, and unable to take action against Dahlia, he becomes Phoenix's rival as a prosecutor, and to thwart a plot on Maya's life, sets in motion a plan that leads to Case 3-5 and causes Misty Fey's death rather than go to Phoenix for help.
In MOTHER 3, Fassad, in his "new" form attacks Lucas and his friends when they try to pull one of the seven needles, saying that they pushed him off Thunder Tower, even though his fall was actually caused by his own bad habit of leaving banana peels everywhere.
In the Invader Zim episode "Battle of the Planets", Tallest Purple orders someone Thrown Out the Airlock for not remembering Zim ruining Operation Impending Doom I. His response afterward:
"That was the wrong guy but... that's okay! I think everyone gets the point!"
Happens all the time on Ed, Edd n Eddy. When one Ed does something, all of them (or one Ed that had nothing to do with it, usually Edd) get punished. On the Halloween special, Ed goes around beating up people and EDD AND EDDY are beaten up instead and Ed goes unharmed, and in the episode "All Eds Are Off," Ed contaminates the pool with gravy and Eddy receives detention for it instead.
Attempted in one episode of Courage the Cowardly Dog when evil eggplants want to attack Muriel because she eats eggplants. Courage dresses up like an eggplant and tries to convince the eggplants to attack the supermarkets instead, but his plan fails when they find out he isn't an eggplant.
The Clock King from Batman: The Animated Series goes after Gotham City mayor Hamilton Hill. Why? Years earlier, The Clock King (then Temple Fugate) was put out of business by a lawsuit brought by Hamilton Hill's law firm. While Hill wasn't specifically the lawyer representing the plaintiff, the Clock King does consider him completely responsible because Hill also suggested Fugate take his coffee break at a different time...which led to things going worse.
American Dad!: After Steve finds his girlfriend slandered and as a result loses her run for election, he gets revenge on the three popular kids who did it (by having buffalo feces dropped on one, injecting another with fat and giving the final one an STD). He finds out his friends did the slander, and the whole school decides to get revenge on all of them, despite Steve protesting that it was their fault (and while it was, he was the one who caused the very serious attacks on the three, making his friends the ones who had the retribution misplaced upon them).
In the Thomas the Tank Engine episode "Trust Thomas", James angrily bumps the troublesome trucks because he has to do Percy's work while he's away at the harbor, but after the trucks find out that Thomas agreed to do James' work, even though James was playing sick, they decide to play tricks on Thomas instead since "one engine is as good as the other".
Bullying and abuse is usually this. Bullies and abusers usually punish people who had little or nothing to do with their insecurities.
The Nazis did this to anyone at anywhere and anytime whenever a German soldier was killed by partisans. They obviously didn't care though... so long as someone paid the price and the message got through to the perpetrators. They would even go so far as to destroy entire villages if they were remotely suspected of harboring partisans and even allied personnel.
The "You wouldn't steal a car" campaign against digital piracy, inflicted only on those who actually buy the DVDs.