A Facebook spokesperson told Engadget that the move was a mistake and has since been corrected, but didn’t explain why. “We apologize to those affected by this issue,” the spokesperson said. “These accounts were removed in error and have been reinstated. We are reviewing what happened in this case and are taking steps to ensure it doesn’t happen again.”

The incident may have been relatively brief, but underscores complaints about inconsistencies in Facebook’s moderation of hate speech. It may inadvertently ban anti-racists, but it will occasionally let overt racists slide. Music journalist Guy Shankland told OneZero that you could find Facebook pages devoted to neo-Nazi bands, for instance. Facebook may catch many of the conspicuous hate purveyors, but its methods still aren’t foolproof.