I can't remember any occasion in any country where I have given the 'bird', to anyone at any time, maybe at some point as a 12 year old in the play ground perhaps. I don't understand why anyone would risk a major confrontation with locals over an anger management issue.
In many parts of SE Asia many locals and farmer types carry small arms, if you give them the bird at traffic lights or wherever they will shoot you dead in your seat and will then happily let the police lead them away to jail. They may be out in 3-4 years if they plead guilty and there have been occasions where the judiciary have not given a custodial sentence as they buy into the argument that there was extreme provocation. Just don't do it, no point arguing about it. It's part of the 'terms and conditions' of living a tax free life in the Middle east and Asia.