The FBI is probing hack attacks on celebs after nude photos of Scarlett Johansson were leaked onto the web last night.

"The FBI is investigating the person or groups responsible for a series of computer intrusions involving high-profile figures," Laura Eimiller at the Federal Bureau of Investigation office in Los Angeles told AFP.

She refused to name any of the celebs involved "due to the pending nature" of the inquiry.

Nude photos and videos of High School Musical star Vanessa Hudgens were pinched from her email account and distributed online in March. She was reported to have gone to the feds over the incident.

Celeb tittle-tattle site TMZ said at the time that about 50 actors and musicians, including Johansson, were the victims of a gang of hackers who were targeting phones and computers looking for titillating photos and gossip.

"What traditionally was called computer intrusion can nowadays mean anything from compromise of a desktop, a laptop, an iPad, a phone or really any device with which one can access personal information via the internet," Eimiller said last night.

Sophos Security's Graham Cluley said celebrities deserved privacy on their personal phones and emails as much as anyone else, but the hacks should teach everyone an important lesson in security.

"If you must take nude photos of yourself, don't leave them on your phone or store them in your email," he said. ®