A yearlong celebrity hacking scandal dubbed "Operation Hackerazzi" culminated Wednesday in the arrest of Christopher Chaney, a 35-year-old Florida man who allegedly acted alone. His mischief made international headlines in mid-September when he allegedly stole nude photos of actress Scarlett Johansson from her cell phone and leaked them to celebrity websites. But she's not alone — more than 50 celebrities are among the scheme's alleged hacking victims. Five key questions:

Who else was hacked?
Besides Johansson, the scheme involved Mila Kunis, Christina Aguilera, and The Secret Life of the American Teenager actress Renee Olstead, says the Associated Press. According to Lindsay Powers at The Hollywood ReporterHigh School Musical's Vanessa Hudgens and former Dancing With the Stars cast member Julianne Hough are "also believed to be on the list." Adrian Chen at Gawker adds Miley Cyrus, Natalie Portman, and Ali Larter to the list of celebrities who were allegedly hacked.

And what happened to the alleged culprit?
Christopher Chaney was arrested Wednesday and charged with 26 counts of identity theft, unauthorized access to a protected computer, and wiretapping. He is accused of hacking into accounts on computers, cell phones, and other devices belonging to more than 50 people. Federal authorities said Wednesday that Chaney's arrest follows a yearlong investigation into celebrity hacking. Chaney has already all but admitted his guilt, saying he was "almost relieved" when the FBI seized his computer.

How did he do it?
Beginning last February, Chaney allegedly hacked the Google, Apple, and Yahoo email accounts of celebrities, according to Greg Risling and Robert Jablon at the AP. He was purportedly able to guess their passwords by monitoring social media and digging through other public information about the stars. (For example, in an unrelated 2005 hacking attack on Paris Hilton, says CNN, a different hacker figured out that the hotel heiress' password was "tinkerbell," the name of her chihuahua). Chaney then allegedly hacked their email accounts' forwarding services, so that every message they sent would be forwarded to his own inbox. He was also allegedly able to use a celebrity's contact list to find other celebrities' email addresses and start pursuing new victims. Besides nude photos, which he leaked to celebrity websites, he also accessed "financial information, movie scripts, and conversations he believed to be private," says U.S. Attorney Andre Birotte Jr.

What's the motive?
"There is no evidence that he profited from this scheme," says Risling and Jablon. In an interview with Action News of Jacksonville, Fla., on Wednesday, Chaney said that his actions "started as curiosity and it turned to just being addictive." The idea of "seeing the behind-the-scenes of what's going on with people you see on the big screen" bewitched him. He's issued an apology, saying that what he did was "the worst invasion of privacy someone could experience."

What now?
Chaney was released on $10,000 bail, under the condition that he does not use a computer or internet-accessible device. If he's convicted on all 26 counts, he faces a maximum of 121 years in federal prison. By itself, the aggravated identity theft charge carries a mandatory two-year prison sentence. Birotte says he hopes the lesson from this scandal is that people, celebrities or otherwise, will take internet security and privacy controls more seriously.

Sources: AP, Gawker, Hollywood Reporter, LA Times, TMZ (2)