CCTV plays a massive role in everyday life now with cameras on the streets, in shopping centers, business properties and many homes,  It’s almost everywhere you turn!  It also played a big role in catching the culprits behind the Boston Marathon bombings, which got us thinking about other crimes where CCTV has proved significant in bringing the people involved to justice.

The argument for greater surveillance is straightforward. Horrible events in places like Boston remind us that we’re vulnerable. The best way to limit events like this is to accept 24-hour surveillance in public spaces.  When you see someone maimed by bomb shrapnel, privacy concerns sound coldly abstract. No amount of security can completely eliminate risk, so it’s difficult to know where to draw the line.

Are 10,000 cameras really twice as good as 5,000? In a tragedy aftermath, it can be tough to have a serious conversation about how much to invest. But when the goal is to push risk as close to zero as possible, spending can asymptotically stretch into infinity. The post-9/11 investment legacy is apparent in the near-ubiquitous presence of law enforcement CCTV cameras. For instance, New York City has more than 4,000 cameras in Manhattan alone, according to the American Civil Liberties Union. Chicago’s linked public and private security cameras number around 10,000. But based on international comparisons, there’s still a lot of room for U.S. surveillance to grow. In London, the Xanadu of winking, digital eyes; surveillance cameras total an estimated half-million.