Law enforcement officials plan to use a combination of tried-and-true tactics, such as curfews, and newer techniques, such as monitoring social media websites, to fight the latest criminal phenomenon: flash mobs. "This is an old crime being organized with new tools. There's nothing new about groups of people assaulting people and robbing, but what's new is the technology," said Jerry Ratcliffe, chairman of the Department of Criminal Justice at Temple and a former London police officer. Flash mobs "take advantage of opportunities. Those opportunities are that the victims are outnumbered by the group and that there is an absence of law enforcement."