Taylor Swift used facial recognition technology at her live performances so that technicians running the system could then check those face scans against a private database of her stalkers. The company that provided the scanning and analysis service appears to be this event counterterrorism division of Oak View Group, which has received a fair amount of press. Part of the reason they've been in the press so much: all the deadly attacks at big entertainment events around the world lately. There is now big demand for serious security at live events the size of a Taylor Swift concert.