But in China, you are more likely to be picked out by one of thousands of police surveillance cameras which link people to crimes through advanced facial recognition technology.

That's what happened last week to a 31-year-old man who was held by police for questioning over an "economic dispute" as he waited with more than 60,000 fans of Hong Kong's Jacky Cheung for a night of pumping Cantopop.

The suspect, who was identified only as Mr Ao, had driven almost 60 miles to the concert in the south-eastern city of Nanchang with his wife and several friends, reports say.

But shortly after the music began, police approached him to say that his facial features indicated he was wanted in connection with an economic crime they had investigated in the nearby Guangxi region.

"The suspect was shocked that he was found among tens of thousands of people, " said Li Jin, a local police officer, according to the China Daily.

It's the latest example of facial recognition being used to catch suspects for a wide range of crimes and misdemeanours in China.