this is rather cool (forgive the pun)
Full article see
here
The US have developed a "ray gun" that blasts heat, apparantly it'll be useful at despersing crowds in a non violent way..
But that's not all... there planning sprayable "black ice" see
here...
So no more tear gas then, we're just gonna be cooked while slipping on our a$$es... better than being choked and blinded (i guess..)