Thanks to AR, VR, and digital impersonation we can’t trust what we see and hear.

Security for Taylor Swift at California’s Rose Bowl in May 2018 included a facial recognition system monitored from almost 2,000 miles away.

A kiosk set up to show highlights of the singer’s rehearsals secretly recorded the faces of onlookers, which were sent to a “command post” in Nashville, Tennessee that attempted to match those images to hundreds of images of known Taylor Swift stalkers, according to Rolling Stone.

“Everybody who went by would stop and stare at it, and the software would start working,” Mike Downing, chief security officer at live entertainment security company Oak View Group, who personally attended the event, said. Oak View Group did not immediately respond to a request for comment.

It’s unknown whether the footage was kept, or if it even identified any real stalkers—and if it did, what happened after they were identified.

But concert venues are typically private locations, meaning even after security checkpoints, its owners can subject concert-goers to any kind of surveillance they want, including facial recognition.

Looking for more in-depth coverage from Quartz? Become a member to read our premium content, and master your understanding of the global economy.