(DIGBOSTON) — Nobody at either day of last year’s debut Boston Calling partied with much expectation of privacy. With an army of media photographers, selfie takers, and videographers recording every angle of the massive concert on Government Center, it was inherently clear that music fans were in the middle of a massive photo opp.

What Boston Calling attendees (and promoters, for that matter) didn’t know, however, was that they were all unwitting test subjects for a sophisticated new event monitoring platform. Namely, the city’s software and equipment gave authorities a live and detailed birdseye view of concertgoers, pedestrians, and vehicles in the vicinity of City Hall on May 25 and 26 of 2013 (as well as during the two days of a subsequent Boston Calling in September). We’re not talking about old school black and white surveillance cameras. More like technology that analyzes every passerby for height, clothing, and skin color.

Along with a dashboard that displays real-time alert data from social media and other nodes of input, city agencies captured thousands of faces using more than 10 cameras capable of intelligent video analysis. Their objective? To detect traffic congestion and suspicious objects, screen people for possible forensic identification purposes, and conduct real-time video analytics. Nevertheless, more than 50 hours of recordings — samples of which are highlighted herein as examples — remain intact today.

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