A few years ago, my friend and I went on a field hockey camp in France. On the dayo before the last day we all went to a water park. It was pretty lame to say the least, but there was like this one really fast waterslide. The problem was that there was a huge line where you had to wait around 45 minutes. We decided to stand in line with our Russian friend (who helped us rig the casino event that got organised at the camp a few nights earlier.)
We keep waiting, and all of a sudden we see a group of like 30 kids from the camp arriving. We yell at them that we held a spot for them and that they should join us. So, 30 somewhat kids jump the queue and join us. The people waiting behind us start losing their shit, babies start crying, all hell breaks lose. Security got called and asked us all to leave and go all the way back to the start of the queue. Obviously that's not what we had in mind.
My friend calls our Russian companion and tell shim to threaten the security guards by pretending that he has a gun and will shoot them. The next time I know this kid starts yelling at them in Russian, the only words I understood were 'Kalashnikov' and some fake gun sounds 'Prrrrrrt prrrrrt'. Those security guards completely lose their shit, start calling for back-up while they brutally escort the kid out of the queue. At this point my friend and I snuck in front of the entire crowd and went from the slide.
It's 5pm and we need to assemble at the entrance. We arrive and we see the headmaster of the camp (the place where the camp took place was a school during the year and he was the principal) talking to one of the security guards and 3 policemen. Apparently they also locked the Russian kid into a holding cell or whatever.
That evening after dinner my friend gets called to the headmaster's office, and tells my friend that the Russian kid explained everything. Both my friend and the Russian kid get expelled and have to leave first thing in the mourning. So, it's mourning and my friend gets put on a train back home. And the Russian kid on a plane back to Russia (this was his first week and he was supposed to stay there for 6 weeks) I was devastated, because besides some other Russian kids that kind of worked for us, I didn't know anyone else.
I spent the day in my room plotting the ultimate revenge plan. I couldn't come up with anything as I walked into the bathroom late at night, and I couldn't help but notice that the standing urinal kept flushing every 2 or so minutes. Thinking about the damage I could strike upon those who expelled me, I took tons of toilet paper and clogged the toilet.
Next mourning, I wake up to the fire alarm, and notice that there's a water pool in my room. I open the door and the entire hall is under water. People crying, pulling their luggage out of their room, and I'm just standing there laughing with my head sticking out of the door. I packed my bags and went home, never heard of those people again.
I decided to leave out the casino story because it's not really relevant to the story.
tl;dr: We got Russian kids to work for us, rigged a casino, got one of the Russian kids expelled for terrorist activities, and I set a part of the building under water.
Also, I was a fucking asshole, but I promise I'm a good person now. :)