I've never actually seen a sim prank a toilet, but I see the results everywhere I go, and it's extremely annoying. Not so much that goofballs do this autonomously, but that there's no way to undo it, even when you can clearly tell by the purple smoke that the toilet has been tampered with. Careless sims walking into a trap is one thing, but me as the player being able to recognise the trap, but still having to take one for the team to defuse it is simply frustrating, and not the kind of drama that players who complained about nothing bad ever happening in the game were asking for. What I do on public lots is go into Build Mode and replace the pranked toilets, but that's not an acceptable long-term solution.