Every country has their own set of obscene gesture unique to their culture. A simple thumbs up is not a good idea in the Middle East, Russia, Greece, Sardinia, Western Africa, and Latin American countries. Even though this means good job or ok in western cultures in these places it refers to "sit on my erect penis." In southern Sardinia, where the gesture is particularly obscene, don’t try hitchhiking!
The common ok sign seen all over the U.S. is never ‘ok’ in Brazil, Germany, and some areas around the Mediterranean. This is because this ‘o’ represents an anus, which means you are calling the recipient an asshole.
The Palm-Back V surprisingly does not mean “peace” in the UK, Australia, New Zealand, and Italy. Instead of “peace” this gesture symbolizes "up your ass" or "fuck off." George Bush, Sr. famously gave the sign to Australians in 1992, thinking he was giving the peace sign.
The Forearm Jerk, slap a hand down on the opposite bicep and then raise that arm into a fist, is obscene in France, southern Europe, the Mideast, and the U.S. This is expressing "Fuck off!" or "Up yours!" In France it is called the bras d'honneur or arm of honor....