Christopher Chaney pleaded guilty in Los Angeles federal court to unauthorized computer access, wiretapping and other felony charges contained in a criminal indictment.

He faces up to 60 years in prison when sentenced in July.

Chaney, who admitted hacking the emails of more than 50 celebrities, was arrested in October 2011 after an 11-month investigation named "Operation Hackerazzi" by the FBI.

His activity resulted in nude photos of Johansson and a bubblebath picture of "Black Swan" actress Kunis reaching gossip websites.

Johansson said later that the photos of herself topless and wrapped in a towel with an exposed backside were taken for her then husband, actor Ryan Reynolds.

Chaney admitted that he had emailed many of the photographs and other personal information that he stole from celebrities to another hacker and to two entertainment websites.

"Today's guilty pleas shine a bright light on the dark underworld of computer hacking," said United States Attorney André Birotte Jr, whose office prosecuted the case.

"This case demonstrates that everyone, even public figures, should take precautions to shield their personal information from the hackers that inhabit that dark underworld," Birotte said in a statement.

(Reporting By Jill Serjeant; Editing by Bob Tourtellotte)

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