Taylor Swift has stumbled into the somewhat delicate matter of privacy concerns with her high-tech effort to identify stalkers at her spring Rose Bowl concert in California.
Fans of the pop star were unknowingly monitored by facial-recognition technology at Swift’s May performance at the stadium, according to a Rolling Stone report. The system, built into a kiosk showcasing rehearsal footage for Swift’s Reputation tour, was intended to weed out people who threaten the pop star.
Images taken at Swift’s performance, which boasted a guest appearance by Shawn Mendes, reportedly were sent to a “command post” in Nashville to be cross-referenced against a database that included hundreds of people who had stalked the singer in the past, 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 of Oak View Group, an advisory board for concert venues, including Madison Square Garden and the Forum in Los Angeles, told the magazine.
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 has been the target of a disturbing number of stalkers. Earlier this month, a man named Roger Alvarado pleaded guilty to attempted burglary and criminal contempt after breaking into Swift’s New York City home in April, taking a shower, and falling asleep.
The home invader accepted a plea offer of six months in prison and is scheduled to be formally sentenced later this month.
The same month as the New York City break-in, a masked man was arrested on suspicion of stalking Swift after he was found outside her Los Angeles home with ammunition, a knife, rope and gloves in his car.
Concerts are technically private events, and organizers are allowed to surveil attendees as they see fit without notifying them, The Guardian notes.
For Swift fans concerned about their privacy, the singer is providing a way to watch her Reputation show from home. Swift announced on Thursday that a concert film of the tour is heading to Netflix.
This article originally appeared on HuffPost.