According to federal documents released Wednesday, Christopher Chaney of Jacksonville hacked Google, Apple and Yahoo email accounts from last November through February 2011.
In many cases, he devised a way to forward a copy of every received email to an email account he controlled. This allowed Chaney to continually receive the hijacked emails even after a password had been reset.
There were more than 50 victims, including actress Renee Olstead, pop star Justin Timberlake and singer Miley Cyrus.
Chaney allegedly used various aliases including "trainreqsuckswhat," "anonygrrl" and "jaxjaguars911." He is charged with 25 counts of identity theft, unauthorized access and unauthorized damage to a protected computer.
The arrest and charges involve "Operation Hackerazzi," a yearlong FBI investigation of computer hacking that targeted Hollywood celebrities.
Nude shots of Johansson appeared on an Internet site earlier this year and TMZ.com reported that hackers stole them from her cellphone.
Authorities say Chaney was not doing this for money. They believe he was hacking just for personal gratification.
Chaney made his first court appearance in Jacksonville.
He was charged with 26 counts of identity theft, unauthorized access to a protected computer and wiretapping. If convicted, he faces up to 121 years in prison.
Chaney is accused of damaging email servers that caused losses of at least $5,000 per instance.
He was released on $10,000 bond.
Celebrities and people in the news have long been targets of privacy invasion but concerns have redoubled in the Internet age.
Publisher Rupert Murdoch in Britain closed down the News of the World this year after contentions that the tabloid hacked into people's phones in the hunt for stories.
The Associated Press contributed to this report.