First Amendment? We don’t need no stinking First Amendment!
This is also what going to work on West 34th Street felt like during the Republican National Convention in 2004, having to pass a phalanx of armored personnel carriers and military-equipped police, carry and present identification and be subject to interrogation for going out for a sandwich.
Where are the tea-baggers when you really need them?
Inspirations and Aspirations 
Tea-party Demonstrators assemble peaceably and avoid confrontation. Anarchists and Anti-business types are more emotional and demand instant gratification. Throwing rocks and Molotov at police does not change policy, and your message gets diluted if not drowned out.
Ghandi and MLK taught us how to protest, alas the young and foolish never want to listen.
Certainly doesn’t seem to be any rock or bomb throwing provocation in this video. The provocation seems to be a camera. Far less of a provocation than carrying a loaded weapon. At least, IMHO, as they say in anagram land.
It’s not the left wing that’s babbling about violent revolution:
Seattle and Quebec were not peaceful. Anarchists treat the G20 as a chance to raise hell. I know you know what “tea-bagging” is, there is no need for vulgarities.