^I was in Turkey during the May day riots - got some great photos mainly of the TV crews / Media balanced on rooftops etc. Was a ball ache getting to my hotel as they had closed all the streets and we had to get the riot police to open the barriers for us etc. Was pretty surreal as there were hundreds of armed police, riot squads etc and me walking past them with my suitcase :D - I was itching to take some photos but thought better of it.
If gassed then sniffing on onions really helps (makes you cry so flushes the shit out of your eyes) - failing that then rinse your eyes with milk (erm so I've been told).