Facebook content moderators are instructed to leave videos of violent abuse on the site to improve user experience, an investigation has found.

When dealing with a graphic violent post, moderators are told that they have three options — ignore it, delete it, or mark it as disturbing, which places restrictions on who can see the content.

Clips showing the “repeated kicking, beating or slapping of a child or an animal by an adult”, “the inflicting of a burn or a cut wound by an adult” or “the tossing, rotating or shaking of an infant too young to stand by their wrists, ankles, legs, arms or neck” are not taken down. Instead they are marked as “disturbing child abuse” and remain accessible to anyone who claims…