I know what non-lethal means. However, a tear gas canister CAN be lethal if it hits you directly in the head. Scott Olsen didn't die, but he could have. That was my point.
I agree that burning the American flag was wrong. However, as I explained earlier in this thread, I consider it to be a rather petty matter considering how people use the flag as a means to justify killing innocent civillians. I find that to be quite hypocritical.
Also, I think you've got the chronology of the events mixed up. The flag burning happened towards the very end of the protest. The time when the protesters threw plastic bottles at police happened AFTER the police threw a smoke bomb. When the protest reconvened later that day, before the flag burning, they were kettled and escaped and then kettled again and 400 were arrested.
Don't get me wrong, I'm not neccesarily trying to justify the protesters actions. On the contrary, I find any kind of violent reaction to be very very very stupid, reactionary, and backwards. However, at the sametime, I feel like the police were out of line, as usual, and that in a way they threw gasoline on the fire.
Show me the evidence.