We've all heard the story of the Hatfields and the McCoys -- they're the two American mountain clans who carried on a decades-long feud over a pig and a poke . There's probably no one who has, or ever will, quite match the Hatfield-McCoy grudge in terms of either duration or intensity, but that doesn't mean there aren't a few contenders out there giving it their best.

5 The (Crazy) Man Who Never Forgives or Forgets

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Matthew Mundschau was just your average Milwaukian -- that is, if your average Milwaukian makes a habit of keeping a detailed mental checklist of every single person who's ever wronged him. Oh, and by "wronged him," we don't mean "nailed his girlfriend" or anything like that; we're talking more along the lines of "drove too slowly in traffic."

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Objects in mirror are crazier than they appear.

We're not sure what exactly the final straw was. All we know is that one day in 2003, Mundschau decided it was damn well time to pay back some of the people on his decade-long grudge list. So he grabbed his fluorescent spray paint, headed to the first address on his list and proceeded to cover the house with obscenities, threats, taunts and presumably a veritable wealth of fluorescent dicks. So what had this person done to deserve having his house transformed into a glowing bonerfest? Mundschau blamed the 75-year-old owner of the house for getting him fired from a crappy supermarket job ... 10 years earlier.

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And Mundschau wasn't done. Next he found the house of a man who had intervened in a fight Mundschau was having with a girl in a parking lot five years earlier. He not only spray painted the house, but also gave the homeowner the classic "dump all the potted plants into the hot tub" treatment. After he finished his angry dump, he paused just long enough to slash a few tires before moving along.

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"Abusive dick, am I? Would an abusive dick vandalize your home for no reason? I think not!"

At a third house, he apparently ran out of spray paint and switched instead to paint stripper, which he dumped all over the cars parked at or around the house. What did this person do? Mundschau believed she had cut him off in traffic.