[oozcitak]

It would be interesting to see how Google would handle the fig sign [1]. It represents the letter T in ASL, but it is considered quite a rude gesture (cunt in Turkish, for example) in many Eastern-European cultures.

[1]: http://en.wikipedia.org/wiki/Fig_sign

[falling]

Much easier: the V sign is considered rude and offensive even in many English-speaking places.

[mjwalshe]

Also some V variants are considered iconic Churchills V sign, which arguably could be considered rude to french people (it was a taunt from English archers to the french)