3.5% is the number that experts say cause a "tipping point" to create a trend that can change society. See Mark Penn's "Microtrends," or Malcolm Gladwell's "Tipping Point."

We don't necessarily need all 3.5% in the streets, though, although it is impressive to see, and will attract more participants. Those at home, keeping up with the news, pressuring their elected officials, debating and promoting the issues on line, talking to family/ friends/ neighbors/ coworkers, etc., are all part of the 3.5%, and they are making different kinds of impacts that the protests won't.

Just like they want to "flood the zone" with propaganda and immoral behavior, it's important that we "flood the zone" with bold resistance.