That sink is the shit. I've never seen a sink so scribed up. Must have come from a totally destroyed bathroom.
I agree with you that I wouldn't want my hands near where someone's ass sat down or where piss often comes in contact, but I also agree that scribes in toilet seats are actually very interesting. The plastic is probably easy to get deep into and no one ever replaces or removes a toilet seat so they run forever. They actually make me laugh when I think about someone bending down to scribe their shit on one.
Same with urinals. My school has scribes on top of and inside of urinals. VERY ghetto and grimy. That cracks me up.