A former Facebook contract employee has lodged a suit against the company, alleging that content moderators who face mental trauma after reviewing distressing images on the platform are not being properly protected by the social networking giant.

Facebook moderators under contract are “bombarded” with “thousands of videos, images and livestreamed broadcasts of child sexual abuse, rape, torture, bestiality, beheadings, suicide and murder”, the lawsuit said.

“Facebook is ignoring its duty to provide a safe workplace and instead creating a revolving door of contractors who are irreparably traumatized by what they witnessed on the job,” Korey Nelson, a lawyer for former Facebook contract employee Selena Scola, said in a statement on Monday.

Facebook in the past has said all of its content reviewers have access to mental health resources, including trained professionals onsite for both individual and group counseling, and they receive full healthcare benefits.

It did not respond to a request by Reuters for comment on Monday.

Currently, more than 7,500 content reviewers work for Facebook, including full-time employees and contractors.

The social network has faced regulatory scrutiny over not doing enough to prevent content such as fake news and hate speech on its platform, and its CEO, Mark Zuckerberg, has vowed to step up efforts to counter it through mass hirings and use of artificial intelligence.

Nelson’s firm is seeking class-action status for the lawsuit.

Scola worked at Facebook’s offices in Menlo Park and Mountain View, California, for nine months from June last year, under a contract through Pro Unlimited Inc, a Florida-based staffing company.

The case, Scola v Facebook Inc and Pro Unlimited Inc, was, filed in the superior court of the state of California.