Twitter has banned the accounts of far-right extremist group the Oath Keepers and its founder, Stewart Rhodes. According to the Southern Poverty Law Center, the group is one of the US’s largest anti-government movements. It claims to have tens of thousands of members, many of whom identify as former law enforcement and military. The group recently tweeted there would be “open warfare against the Marxist insurrectionists (its shorthand for Black Lives Matter activists) by election night.”

A spokesperson for Twitter told Engadget it banned accounts associated with the Oath Keepers for violating its policies on violent extremist groups. “There is no place on Twitter for terrorist organizations or violent extremist groups and individuals who affiliate with and promote their illicit activities,” the company says on the policy page. “We examine a group’s activities both on and off Twitter to determine whether they engage in and/or promote violence against civilians to advance a political, religious and/or social cause.”