At a Swift concert in California's Rose Bowl this past May, Swift's security teams installed a kiosk that displayed highlights of her rehearsals for the show that fans coming to the concert could stop and take a look at.
The system, built into a kiosk showcasing rehearsal footage for Swift's Reputation tour, was meant to weed out people who threaten the pop star. Anyone who stopped to watch the screen had their faces scanned and sent to a command post in Nashville, Tennessee where it was cross-referenced with a database of the artist's known stalkers, of which there are fucking hundreds.
Downing said he was invited to attend the concert by the maker of the facial-recognition software, a technology increasingly used at large events.
Swift, who has sold more than 40m albums worldwide and won 10 Grammy awards, has been the fixation of many stalkers in recent years.
The security may seem a little extreme, but last week one of Swift's stalkers, Roger Alvarado, was sentenced to serve six months in prison after he broke into her apartment in New York City.
A third stalker, Mohammed Jaffar, was also sentenced to six months in prison earlier this year after threatening Swift with violence and trespassing at another of Swift's NY homes.
While some have raised privacy concerns over the ownership and storage of the images, concerts are technically private events, and Swift has no obligation to notify ticket holders that they may be surveilled.
A second man, Julius Alexander Sandrock, was also arrested in April for trying to gain entry to her home.
Rumors that a video of the tour was being made for or by Netflix have been circulating among fans since mid-November, after those who met Swift backstage in Tokyo signed disclaimers for the streaming service.