This is a classic. You can't really tell what's happening until you look closely at the wandering hand. Gotta get one for my sister. She thinks that every time a guy bumps into her, it's accidental. Geez.
A funny shirt which warns you of..." "Beware of Perverts" (Chikan chuui), with "Dangerous Persons are in this Area" below. Those crazy Japanese. :)
Useful advice in any language and any country.