This whole topic is lolz
One time, someone stuffed wet paper towels into the drain and a bunch of people pissed all over it. There was a puddle of piss a good have inch deep around the drain, because the floor was slightly angled downwards around it. You always find wet paper towels stuck to the ceiling, too.
Most people at my school don't intentionally stuff up the restroom (get it) for no reason, most just pretend to have to take a piss then sit in there and look at their phone for a few minutes.