They can't care less about stamp collection but certainly they know stingy and vinapu are not going together well so Keith and rob are right - it's pockets they watch.
As for bars there are some - Jupiter, Fresh Boys, Dreamboys where I enjoy fair amount of anonymity so they feel free to great extend to ignore that old troll me.
Speaking about pockets, one of my regular guys once took jokingly to check contents of one of my shirt pockets. Joke did not go well with me and as far as offs are concerned , he is dropped for good from list of prospective philatelists.