"Bummer, you don't appear to have any messages"
We got a very very angry message from a user one day, telling us they didn't appreciate us using the word "bummer" and that it was extremely offensive. Apparently it's a slang term in the UK.
Internationalization is tough :\
We got a nasty email from someone who got the password DUUD7573. They were insulted as a pre-operative transsexual that we were calling them a "dude" and that we must've known they were a transsexual.
The best way to handle this is say "No, it's at random." and let people un-offend themselves.
Just as other words, e.g. referring to illegitimate children (I think even medical doctors no longer use it) are used differently to their original meaning. The meaning of most slang/swear words are - ahem - bastardised, if you will.