The kind of surveillance cameras that helped identify the Boston Marathon bombers are expected to play a bigger role in the future, not to deter crime but to catch criminals after the fact, former federal Homeland Security official Stewart Baker tells NPR. Boston has only 60 cameras controlled by law enforcement. Those used in the Boston case were privately owned. “In a way, private, distributed surveillance cameras create a kind of network of ‘little brothers’ instead of a Big Brother, so you get the same benefits to a great extent without incurring the risks to civil liberties,” says Julian Sanchez of the Cato Institute. Ben Wizner of the American Civil Liberties Union doesn’t object to the way police used surveillance in Boston. “I think, in some ways, this is an easy case because when there’s a crime of this nature, there’s no problem whatsoever for the police to get any kind of permission they need from judges in order to conduct surveillance,” he says.