The South Carolina prison system disciplines prisoners accessing Facebook with the same severity it would for murder, rape, rioting, escape and hostage-taking, according to the Electronic Frontier Foundation.

South Carolina's Department of Corrections punished nearly 400 inmates of using social media over the last three years, with some of the cases resulting in lengthy solitary confinement.

The statistics, collected by the Electronic Frontier Foundation and released on Thursday, highlight the state prison system's strict social media policy and Facebook's involvement with the removal of inmate profiles. EFF, an Internet civil rights advocate group, learned of the information through a Freedom of Information Act request.

"Facebook really shouldn't be acting as a government censor," said Dave Maas, media relations coordinator and investigative researcher at EFF. "There's lots of legitimate reasons why a prisoner should want to contact the outside world, whether that's bringing attention to prison conditions or information about his case, or communicating with his own family."

Facebook did not reply to a request for comment.

The South Carolina prison system has asked Facebook to remove hundreds of inmate accounts. The world's largest social network obliged, using its terms of services agreement as its rationale, according to EFF. That services agreement states users can't use an alias or share passwords with third parties. Prison systems can ask Facebook to remove inmates' accounts using its "Inmate Account Takedown Request." The EFF is calling for more transparency when it comes to these requests.

The use of social media is a serious violation for inmates in South Carolina. The policy to stem communication from the outside world is meant to stop inmates from conducting criminal activities from the inside.

The prison system characterizes social media use as the same level of crimes like murder, rape, rioting, escape and hostage-taking, according to the Maas. In 16 cases, inmates faced more than a decade in disciplinary detention, a punishment that includes solitary confinement and the loss of visitation privileges. One inmate received more than 37 years in isolation, according to the EFF.