Absent the net, we certainly couldn't have organized in 190 countries around the world. It's no substitution for face to face interaction - that's why we have "days of action" where people are in real contact with each other - but it's the cheap (and low-carbon) way to do an awful lot of the planning and organizing. And we can build, for $20k, a website as good as one Exxon can build for $20 million.