In a first-of-its-kind prosecution, the convicted operator of a “revenge porn” website was sentenced to nearly 18 years in prison, officials announced Friday.

Kevin Christopher Bollaert, 28, of San Diego, was found guilty in February on six counts of extortion and 21 counts of identity theft for running a website that posted nude photos of individuals, as well as identifying information, without their consent, according to Attorney General Kamala Harris.

“Sitting behind a computer, committing what is essentially a cowardly and criminal act will not shield predators from the law or jail,” she said in a statement. “We will continue to be vigilant and investigate and prosecute those who commit these deplorable acts.”

The site, called Ugotposted.com, was one of many revenge-porn outfits to allow anonymous users to post sexually explicit photographs — sometimes of former lovers — without the consent of the photo subjects. But unlike other similar sites, Bollaert’s site required users to submit the subject’s full name, location, age and Facebook profile link, Harris said.

Often the subjects were subjected to harassment online and in the real world, according to Harris.

Bollaert also created another site in an attempt to cash in on the humiliation he wrought on his victims. When victims saw their photos on Ugotposted.com and contacted the site, investigators said, Bollaert would send them an e-mail from Changemyreputation.com, which he also ran, offering to remove the images for a fee ranging from $300 to $350.

Bollaert told investigators that he made up to $900 a month from advertising on Ugotposted.com. His PayPal account indicated he received payments totaling roughly $30,000 from Changemyreputation.com.

He was arrested in December 2013, and his sentence marked the first prosecution of cyber-exploitation in the country, according to Harris.

“Today’s sentence makes clear there will be severe consequences for those that profit from the exploitation of victims online,” she said.

Kale Williams is a San Francisco Chronicle staff writer. E-mail: kwilliams@sfchronicle.com Twitter: @sfkale