His name is Luis Mijangos. A 32-year-old former gang member from Santa Ana who turned to computers after a shooting left him paralyzed.
"The minute you turn on your computer, he's watching you,' said Glenda, one of Mijangos' victims."I felt so violated. I got sick."
"You're paranoid. You live the rest of your life just paranoid," said another victim, Samantha. "He started blackmailing me. He would say, 'Don't piss me off, you (expletive).'"
Mijangos went to federal prison two weeks ago for six years for hacking into more than 100 computers. His victims were young women and teenage girls. Dozens of them were minors.
Federal authorities call Mijangos a "Sextortionist."
"I didn't even know that word existed," Mijangos told Eyewitness News in an exclusive interview. "Another made up word from the federal government."
Mijangos convinced Samantha to send him nude photos. She was 17 and he pretended to be her ex-boyfriend.
"It was like 'Hey, this is my new email,' and from there she fall for it," Mijangos said.
Samantha sent him the photos, but she soon realized she had been tricked.
"He blackmailed me with my pictures in an email saying if I didn't give him more pictures, he'd put them up on my Facebook and MySpace (profiles)," Samantha said. "The worst part was not knowing who it was."
Samantha was merely one of many.
"For many of these victims, the impact was devastating," said Assistant U.S. Attorney Stephanie Christensen, who prosecuted the Mijangos case."Several victims reported irregular behavior with their webcameras. They noticed their cameras were turning off and on."
Mijangos used popular songs on the Internet to sneak viruses into his victim's computers. He said that once they were infected, he had full access to their computers.
"In one instance, a minor victim was having Web sex with her boyfriend. It's happening over the internet," Christensen said."Her boyfriend on one end of Web camera and she is on the other. And (MIjangos) is watching this very intimate activity and he is clicking and he's recording images, over 3,000 of this young girl in this sexually-explicit conduct."
But the so-called sextortionist said he wasn't motivated by sex
"It's clear if you have a camera in your room and it's on and you don't know someone is watching you, you're going to undress, get out of the shower, being in your very private moments," he said.
FBI special agent Jeff Kirkpatrick followed the cyber breadcrumbs straight to Mijangos.
"We found many cases where he'd been studying people, watching peoples computer activity for well over a year," Kirkpatrick said. "He knew what kind of music they liked, who their friends were."
Glenda, another victim of Mijangos, said it destroyed her.
"I kept on changing my passwords and he kept on changing them back. It was like a game to him. Like a mind-game," Glenda said.
Mijangos hacked into Glenda's computer, stole intimate photos and threatened to post them online.
"They were personal pictures that my fianc?e and I had taken for each other," Glenda said.
"He sent me a message and said 'You are pissing me off, so I'm going to teach you a lesson,'" Glenda said.
Mijangos admits he stole the photos, but denies he was the one to post them on Glenda's MySpace page.
"I never published any pictures," he said.
But Mijangos is a hacker who has bragged about his skill at lying.
"My technique is social engineering, which is basically lying to people, make people trust," he said.
"It makes me sick. I think he's sick," Glenda said. "I don't think he thinks he did anything wrong."
Glenda finally called police, which was the catalyst that triggered an investigation by the FBI.
"I had just gotten out of that relationship and that's what gave me the power to say no," she said.
The FBI arrested Mijangos in June of 2010.
"I'm really sorry," Mijangos said. "I'm being honest, I'm being sincere."
Mijangos is also an undocumented immigrant, so it's possible he will be deported when he's released.
So how can you protect yourself? One easy way is to keep your anti-virus software up to date.