What really plunks my twanger is people leave the ash-gaskets on the toilet seat when they're done. What, your precious arse can't touch toe toilet seat bt you expect someone else to touch the ash-gasket your butt sat on?
About 20 years ago I worked in a large computer based company and this was a habitual occurance and a source of aggravation to all. A bunch of us made a pact and whenever we saw someone go in, somebody would check it out right after they left. Sure enough, about three days into this, the culprit was discovered. After it was verified (we caught him twice), the next time he went in a few of us quietly went into the bathroom waited for him right outside the stall door. He was surprised to see five of us there blocking his way and someone said "I think you forgot something". He played stupid and was coaxed back in and, sure enough, there was the gasket. He was red as a beet but he did put it into the crapper. He never did that again and the problem disappeared. And, I won't say where, but he was not native to this country but one where cleanliness is valued. And, yes, word spread about his antics. He didn't have too many close associates after that.