Let's start with the basics of protest and civil disobediance:
1. Climbing the bay bridge to hang signs about the war -- good!
2. Organizing chants, visible signs of protest on the torch route -- good!
3. Sending letters asking the US to boycott the opening ceremonies, etc... good!
...anything non-violent is good.
1. Physically assaulting the torch bearer in an attempt to steal the torch
2. Spraying the torch bearer with a fire extinguisher in an attempt to douse the torch
...etc this is all bad.
This is all bad in a way that makes society unsafe. Because if you turn this around, do you want protesters against gay rights or abortion making physical attacks like this to make their point? I lived through that -- it was called Operation Rescue, and I still have nightmares about that. You don't want to go there.
Doing something "because you can" inspires people on all sides to do similar things. Don't go there, because you won't like it when it comes back at you.
Be loud, be provocative. But be peaceful, PLEASE.