Four men responsible for running an abusive Internet addiction treatment camp in China have been sentenced to prison. They were found guilty Tuesday for illegally locking up 12 young people in solitary confinement for up to 10 days.

The men were referred to in the documents as Qu, Ren, Wu and Zhang. For their roles in running the abusive Yuzhang Academy in China’s Jiangxi province, Wu was sentenced to nearly three years, Ren to two years and seven months, Zhang to one year and 10 months, and Qu to 11 months, CNN reported.

Yuzhang Academy first came under scrutiny in 2017 following allegations from former students that they were locked in small “black rooms” with only a blanket and a pot to use as a toilet. Media reports from the time described the camp as using harsh punishments to “cultivate teenagers’ moral character.”

Camps purported to treat internet addiction began cropping up in China en masse in 2008 when the government deemed the condition a mental disorder.

Hundreds of such camps are currently in operation, with some accused of using beating students or using electroconvulsive therapy.

In 2017, an 18-year-old man was killed only two days after arriving at the camp and was found covered in bruises and scars. In 2014, reports surfaced of a 19-year-old woman who was beaten to death at a camp in Zhengzhou. In 2009, a 15-year-old died at a camp after a series of beatings.

Judge gavel
California's highest court orders a review of the murder conviction of Scott Peterson, accused of killing his wife and unborn child, on allegations of juror misconduct. Joe Raedle/Getty Images