I wince every time I see a photo like this. Several years ago as a volunteer firefighter I was in a house fire and was hit with a hose stream that threw me into a wall. The stream that hit me came from a 1.75" hand line on an adjustable nozzle. The stream the above protester was hit with was likely a smooth bore nozzle, which means water flows unrestricted under high pressure. Getting hit with a stream of water like that would be incredibly painful.
Adem Altan / AFP - Getty Images
A demonstrator falls after he was hit by a jet of water during protests against the government's education policies, at the Middle East Technical University in Ankara, Turkey, on Wednesday, Jan. 5. Turkish riot police used water cannons to prevent the university students from marching to the ruling Justice and Development Party headquarters.