The Boston Calling Music Festival in May 2013 had a great lineup: Fun., Dirty Projectors, and Of Monsters and Men, to name a few. The event also included ten cameras that recorded over 50 hours of video surveillance footage on the thousands of concert goers at Boston's City Hall Plaza. An investigative series by the Boston area free weekly DigBoston recently unearthed this surveillance, which was done on behalf of the city.