Ecologist: In 2008, environmental author Bill McKibben and a group of seven young activists scraped together $30,000, built a climate-awareness website called 350.org, and took to then still-novel social networks such as Twitter, Facebook and Flickr to spread the word.
The strategy was a runaway success: barely a year later, 350.org had evolved into a global movement, and in October 2009 its members staged 5,200 coordinated environmental protest rallies in 181 countries -- the largest concerted political...