Karen "Gary" Kazaryan, 27, admitted that he tricked women into posing nude for him after hacking into their computers.
In July, he pleaded guilty to one count each of identity theft and unauthorized access of a protect computer.
On Monday, he declined to address the court. But in a letter to the judge, the 27-year-old blamed depression and marijuana use for his crimes.
"The lines between digital life and reality were blurred and out of control for me," he wrote, calling his actions "immature and mindless."
As his family sat in the courtroom, prosecutors described how Kazaryan hacked into the Facebook, Skype and email accounts of victims, and then changed the passwords to lock victims out of their own accounts.
Once he controlled the accounts, he searched emails or other files for naked or semi-naked photos of the victims.
Using that information, the 27-year-old then posed online as a friend and persuaded them to strip while he watched via Skype, captured images of them, or both.
Once the women learned of the ploy, he would threaten to post their private photos and coerce women into sending even more nude pictures. In some cases, the suspect posted the nude photos to the victims' Facebook pages when they refused his demands.
U.S. District Judge George H. King said Kazaryan caused "great fear" in his victims, who were "forced to perform in a degrading manner under the threat of exposure."
The prosecutor told the judge that many of the women described the emotional impact of Kazaryan's crime in terms of rape.
"It has made it difficult to trust anyone I meet when someone I know could do something so abominable," one victim wrote in a statement read by Assistant U.S. Attorney Tracy Wilkison. The woman had known Kazaryan from high school.
Kazaryan was immediately taken into custody after his sentencing hearing in downtown Los Angeles.
The suspect was arrested in January by FBI agents on federal computer hacking charges. He was indicted on 15 counts of computer intrusion and 15 counts of aggravated identity theft.
Investigators suspect that Kazaryan victimized more than 350 women, but all of the women have not yet been identified.
About 3,000 images of nude or semi-nude women were found on the suspect's computer, according to prosecutors.
Prosecutors say cases like Kazaryan's should remind everyone to take precautions with their online accounts and passwords. Officials urge people to be prudent when posting images online or to any wireless communication.
Computer users are also warned to ensure their passwords are hard to guess, avoid opening unverified attachments and use reliable anti-virus software.
CNS and The Associated Press contributed to this report.