Inspired by this Cracked article on 7 innocent gestures that can get you killed overseas - it mentions that the innocuous thumbs-up gesture in the Middle East means ‘swivel on this’. I Googled it and Wiki backs this up stating it’s a bad idea in Afghanistan and Iran. But it also says;
Eh? I’ve never heard this before and further Googling gives us nothing. Could any Israeli or Jewish Dopers clear up if it’d be a bad idea to give the thumbs up (or down, or the ‘not sure’ wiggle) in their respective cultures?