Los Angeles (CNN) -- Federal authorities accuse a 35-year-old Florida man of hacking into accounts on computers and other devices belonging to more than 50 people, including entertainers Scarlett Johansson, Christina Aguilera, Mila Kunis, Simone Harouche and Renee Olstead, officials announced Wednesday.
Christopher Chaney of Jacksonville, Florida, was indicted on charges of accessing protected computers without authorization, damaging protected computers, wiretapping and aggravated identity theft, officials said.
"Unfortunately, Mr. Chaney was able to access nude photos of some of the celebrities and some of them were uploaded on the Internet," U.S. Attorney Andre Birotte Jr. said.
A recently circulated nude photo of Johannsson is part of the investigation, he said.
Chaney allegedly "also took financial information, movie scripts and conversations that the celebrities believed to be private," Birotte told reporters.
Chaney allegedly was able to access passwords by monitoring social media and other online sites that the celebrities used, said Steven Martinez, assistant director in charge of the FBI's Los Angeles field office.
"You may have selected a password that's meaningful to you that you may disclose online with friends," Martinez said. "Your pet's name or whatever. That's a clue to a hacker, to start there."
The suspect used several aliases such as "trainreqsuckswhat," "anonygrrl," and "jaxjaguars911," authorities said in a news release.
Chaney also allegedly used public sources to mine data about his victims, which included both males and females, all associated with the entertainment industry, authorities said.
Authorities allege that once Chaney hacked into a celebrity's e-mail account, he would use the contact lists to find other celebrities' e-mail accounts. This allowed him to add new victims, authorities charge.
Chaney made his initial appearance in U.S. District Court in Jacksonville, Florida, on Wednesday afternoon, and was released on a $10,000 unsecured bond with the conditions that he can't use any computer or other device with Internet access and he can't have any controlled substances or excessive use of alcohol, said Laura Eimiller, an FBI spokeswoman in Los Angeles.
Chaney's next court appearance will be at 10:30 a.m. Friday for an identity hearing in the same courthouse, Eimiller said.
Chaney has been indicted on with nine counts of computer hacking for gain, eight counts of aggravated identify theft, and nine counts of illegal wiretapping, Birotte said.
If convicted of the 26 counts, Chaney would face a maximum of 121 years in federal prison, Birotte said. The aggravated identity theft charge alone carries a mandatory two-year prison sentence, he added.
Chaney allegedly also set his victims' accounts to automatically forward their e-mails to his account, Birotte said. This allegedly allowed Chaney to continue to receive celebrities' e-mails even after a password was reset, authorities said.
Authorities allege that Chaney distributed photos of the celebrities that he obtained illegally and offered them to various celebrity blog sites. Some of the illegally obtained files, including private photographs, were ultimately posted online "as a result of Chaney's alleged activities," authorities said in a statement.
The FBI's Los Angeles office said he was arrested as part of "Operation Hackerazzi," which looked into computer intrusions targeting individuals associated with the entertainment industry.
Martinez said authorities have coined a word to describe hackers of celebrities' e-mail accounts: hackerazzi.
"The paparazzi is always chasing them down, and now you have a virtual way of doing it by looking at posts they put on social media sites," Martinez said, explaining the term.
Investigators don't have a motive for Chaney's alleged offenses.
"Motive is always a question in criminal cases and we don't know and we don't care" in this case, Birotte said, adding he is confident of the hacking evidence against Chaney.
The first real case of a celebrity hacking attack was in 2005, when hackers logged into Paris Hilton's phone and stole photos of her, according to Mikko Hypponen, chief research officer at the F-Secure computer security company. Those hackers reportedly were able to break into Hilton's phone by correctly guessing the not-so-secret answer to her security question, which was "tinkerbell," the name of her pet Chihuahua.
In August, rapper Kreayshawn wrote on her blog that her Twitter account was hacked when naked photos of her showed up there.
In March, Vanessa Hudgens of "High School Musical" underwent a similar ordeal after photos were reportedly stolen from her Gmail account.
And in December, police in Germany alleged two young men had used computer-hacking skills to gain access to the e-mail accounts and photos of more than 50 celebrities, according to Britain's The Telegraph, including the likes of Lady Gaga and Ke$ha.
In the wake of the latest celebrity hacking allegations, some have started to assume celebrity photo leaks are the newest front in the so-called "hacktivist" wars, waged by big-name hacking rings such as Anonymous and LulzSec. Those groups have claimed responsibility for taking down bank and government websites.
But security experts said connections between celebrity hackers and groups such as Anonymous are thin or nonexistent.
"It's obviously to gain media exposure, right?" said Kevin Mitnick, a hacker turned security consultant and author of "Ghost in the Wires." "It's like everyone is trying to one-up Anonymous and one-up LulzSec. So somehow celebrities are becoming a target."
CNN's Carey Bodenheimer and John D. Sutter contributed to this report.