Teen heartthrob Justin Bieber found out just how much of a paparazzi magnet he really is when he came face-to-face with a photographer on a video chat site.

The singing sensation popped up on social network Chat Roulette, which lets users see strangers around the world on webcams as they move at random from one person to another.

Open-mouthed Justin looked surprised as he noticed the latest user to appear on his screen had picked up a camera as quick as a flash and reeled off a couple of quick pictures.

The cheeky pap typed a message for Justin, telling him: “UR Too Slow U've Been Papped.”

Justin saw the funny side though and replied: “I'm use to it.”

Then he cut the chat short the chance encounter before any more photos could be taken by moving on to the next user.

A host of celebs including Justin have reportedly been spotted on Chat Roulette.

Paris Hilton, The Jonas Brothers, Ashton Kutcher and Chris Brown are all said to have surprised Chat Roulette users by popping up at random.

Users move through the quick-fire world of Chat Roulette by clicking the “Next” option on screen.

Either party can terminate the meeting or they can hang around or chat online