I've also seen someone pay for the admission fee and fill out the waiver and then proceed to "kill" the activities at a *large* dungeon simple by wandering thru and looking. Nothing you could put your finger on just "creepy vibes".

Thankfully he got bored and left after half an hour and folks recovered quickly after he was gone.

But after that I *know* that there are people I very much don't want interested in me.