Supernova 2008 held day 1 of the three-day conference yesterday in San Francisco's Mission Bay Conference Center. The opening session tackled "defining the challenges", which was admittedly a fairly vague title. Clay Shirky, author of Here Comes Everybody, started off the session taking about the characteristics of organizing groups online and offline. Shirky pointed to prospering examples of organizing groups online such as the Meetup Alliance.The presentation pointed out a number of case studies to gain insights from. From a flashmob being arrested in Belarus for organizing a collective "everyone eat ice cream at the same time" event to Xerox's lack of source code in 1980, characteristic contrasts were made between the ease of online versus offline. It was explained that density and continuity in niche groups used to exist due to inconvenience, but those same aspects need to now exist by design online in order to be able to network and organize effectively.Questions from the audience asked for advice on "community management" (or, lack of a better English phrase, as Kevin Marks stated). Shirky said that a self-policing communities often take care of the problems that arise. Later, Shirky clarified, to my concern of the possibilities for a community run by mob rule, that this mostly works and works when the community knows they can "call a cop at key moments".