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

He was ordered held in custody and faces up to 60 years in prison, plus fines and restitution of about $2.5 million 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.

Other victims included former Disney Channel star Vanessa Hudgens and Renee Olstead, one of the stars of ABC Family's "The Secret Life of the American Teenager". Other victims were identified only by their initials, including J.A., B.P., and L.B.

Chaney, a clerical worker, told a Florida TV station shortly after his arrest that he had become addicted to prying into the affairs of movie stars and did not know how to stop.

His snooping resulted in nude photos of "Iron Man 2" star 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.

Chaney admitted on Monday that he managed to hack into the personal emails of his targets by clicking on the 'forgot password' feature of their accounts and replying correctly to security questions by using publicly available information about celebrities that he found on the Internet.

Once in control of the email accounts, he obtained private photos, business contracts, scripts, and other documents. He went through contacts lists to find other victims and sometimes posed as friends to request more private photos.

Chaney initially had pleaded not guilty and had been free on bail. But on Monday he was ordered to be held behind bars until he is sentenced on July 23.

(Reporting By Jill Serjeant; Editing by Bob Tourtellotte)

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