The use of facial recognition technology in surveillance cameras is common in China, with systems found everywhere from streets, to bus stations, to grocery stores, and airports. Chinese police say they recently used the technology to identify then arrest a man at a music venue attended by over 50,000 other people.

The 31-year-old suspect, who has only been identified by his surname, Ao, was attending a concert by Hong Kong singer Jacky Cheung with his wife and friends last week. The South China Morning Post reports that Ao was shocked when police approached and led him away for “economic crimes.”

Ao had driven 56 miles to attend the concert. He was quoted as saying he felt safe in such a huge crowd and would never have gone if he knew there was a risk of him being spotted. He was identified at the concert’s ticket entrance before being apprehended by police after sitting down alongside other attendees.

“Ao was suspected to be involved in an economic crime and was listed on a national online system,” said police officer Li Jin of Honggutan police station in Nanchang city. "He didn't think the police would be able to catch him from a crowd of 60,000 so quickly,"

Last August, authorities used facial recognition technology to arrest 25 suspects at the Qingdao Beer Festival. And earlier this year, officers stationed at the Zhengzhou East high-speed rail station in Henan province made headlines after they were issued glasses embedded with facial scanning technology.

With 170 million CCTV cameras already in use, China continues to work on "the world's biggest camera surveillance network." It’s expected that millions more will be added over the next few years, many of which will feature forms of AI that include facial recognition. A worrying prospect for a country with such a poor record when it comes to privacy and human rights.