How should the United Kingdom combat the violence that’s raged across the country all week? British Prime Minister David Cameron says the country needs to learn a few lessons from America on how to fight gangs, along with possibly revoking social media and Blackberry service from rioters. What can the U.S. offer as advice for the U.K. on handling gang violence? Tio Hardiman is someone who knows how gang members communicate, and possibly how to stop violence before it starts.  Hardiman is the director of CeaseFire,  a public health group that works to reduce violence in Chicago, where an estimated 100,000 gang members live.