Concept for ya: How would one do a "web street demo"?

[skids]

I just had a thought: What would the web version of a street demonstration be like?

Now don't flame with "get off your ass and go to a real demo" because I'm only thinking of it as an in-addition-to type thing.

Applying some of the rules and characteristics of street demos to the web:

1) It takes place "in public." That would mean, probably, that there would have to be a particular set of websites onto which the netizenry would converge. Of course, the sites chosen would best be one that could take a massive load, and most of the web is private property, but it just isn't effective to hold a rally in your buddy Farmer John's field in East Armpit, so a preexisting site would have to feel the impact. Most importantly, "passers by" have to be able to notice it, even if it is mildly inconvenient for them.

2) You have to be able to see how many people are "there" somehow. Perhaps by signing an online petition.

3) You can shout at a small number of people around you, or broadcast with a megaphone, but megaphones should be in limited supply, perhaps passed around. This is perhaps the most interesting part to try to get right.

4) You'd have to be able to carry signs. Avatars and sigfiles might suffice.

5) The protest should be nonviolent and not lead participants haplessly into legal jeopardy. (Though I've seen some real-life rallies where that rule has been broken.)

6) There would be an organized speech at some point that folks just listen to, though they should be able to cheer and raise a general ruckus at appropriate points.

Anyone else want to point to real life examples or offer other thoughts? This is all just hypothetical daydreaming, so don't take it too seriously.