Alleged sexual assaults at Occupy Wall Street camps have raised concerns about security in a handful of cities, including reports of rape and groping in tents at New York's Zuccotti Park and a sex offender in Dallas having sex with an underage runaway. "These protests have a history of welcoming everyone and just assuming they're on your side," said David Meyer, a professor of sociology at the University of California at Irvine, who studies protest movements. The recent reports of assaults have created a problem the "Occupy" movement is being challenged to address head-on. "We always encourage victims to go...