"Be careful what you twit for," said Andrew Belonsky in Gawker, "because your 140 characters could land you in the slammer." Anarchist and Twitter user Elliot Madison learned that lesson the hard way. Madison was arrested for his role in the recent G-20 protests in Pittsburgh, where -- "like a good 21st century rabble-rouser" -- he used Twitter "to direct his comrades around the mayhem."

Madison said he was only doing things that demonstrators do all the time, said Colin Moynihan in The New York Times, and that his arrest and a police raid on his New York City home was an attempt to "stifle dissent." It's true that mass text messaging has become "a valued tool among protesters," but the Pennsylvania State Police say Madison was using Twitter and police scanners to help people "avoid apprehension after a lawful order to disperse."

This could be a case of "the political power of Twitter being challenged right on it's own doorstep," said Davey Winder in DaniWeb. "When it is someone using Twitter to report on the movements of police during a rebellion in a hostile nation," such as Iran, then U.S. authorities are gung-ho about social media. But our leaders are less thrilled about "the democracy afforded by such real-time micro-blogging" when "the political unrest is nearer to home."