Worst thing anyone has done to your boat

so, I'm building this somewhat off of the "most crap anyone has brought on your boat" thread, and I can think of a lot worse things that people have done to my boat other than bringing out too many gatorades.

heres a couple examples:
#1: my friends brought sunflower seeds on the boat, after I specifically told them not to. they then thought it wold be a good idea to have one of them sitting in the bow and throw the seeds to my friends sitting in the stern so they could try to catch them in their mouth's. you can guess how that turned out.....

#2: (even though this isn't a wake boat, its still a boat nonetheless). I had some friends up to my cottage, but I couldn't entertain them because I had to work all day, so I told them they could take the pontoon and the jetski's out (I hid the keys to the ski boat). When I came back to my place the day my friends were leaving, I walked onto the lake side to see one jet ski half on a hoist that they somehow managed to break, and the other one floating around the end of my dock (luckily it was calm otherwise it would have been long gone). upon further inspection, when they took my pontoon boat out, they somehow managed to rip off one of the backs of the captains' seats in the bow, and when they tried to dock the boat they ran it into the front of my dock so hard that they mangled one of the pontoons so bad that we almost had to get it replaced. not to mention the fact that it took me a solid two days to scrub the carpet from the combination of doritos and goldfish they ground into it.

It goes without saying that my friends from incident two are now "blacklisted".

Im sure you guys have some horror stories of your own. post em up!