Rachel Bilson has vowed not to get snapped without her underwear, slamming careless celebrities who don’t cover up.

The actress, who is currently starring alongside Hayden Christensen in Jumper, is determined not to have her lady parts photographed, and makes sure she is always wearing underwear to stop any unfortunate shots.

She says: "I've seen what the paparazzi can do to someone if she's careless about how she gets out of a car and if she forgot her underwear. Fortunately, I'm not one to forget about underwear. Ever.

"I've had these guys trying to get these shots, crotch shots, I guess, and you think, 'You've got to be kidding. This is the ultimate down and dirty ambush.'

"But it's something you can pretty easily protect yourself from. If that's being a celebrity, then I'm not one. I like my privacy, I like having quality time with my dog.

Bilson, who played Summer in the hit teen show The O.C, added: “I grew up in Los Angeles, my family is in the business, and it's easy enough to avoid the obvious places where you'll run the gauntlet."

We wonder what she would have to say about her naughty former co-star Mischa Barton.