Jared James Abrahams plead guilty to three counts of extortion and one count of unauthorized access of a computer in November.
Abrahams, a computer science student, emailed multiple victims worldwide with threats of publishing revealing snapshots of them on social media sites.
The suspect had obtained the images illegally and threatened to publish the photos if they didn't send him additional pictures or undress for him.
Abrahams "extorted at least 12 young women in their late teens or early twenties in this manner," the plea agreement states. The defendant allegedly used "hacking software" to control 100-150 computers of victims.
Abrahams initially told the judge he has autism and has been under treatment for it for the past 10 years.
CNS and The Associated Press contributed to this report.