Facebook is cracking down on hate speech — but catching anti-racists and musicians’ pages in the purge.

As part of the overreach, Facebook has temporarily suspended hundreds of anti-racist activists from the group SHARP. SHARP stands for Skinheads Against Racial Prejudice – the platform says the pages violate community guidelines. Also caught up in the purge were reggae and ska communities. The platform has not revealed why the pages and musician’s personal pages were banned.

Reddit users speculate that simply liking the SHARP page is enough to prompt a ban. The platform may also be reacting to the word Skinhead in the title – a pejorative used to refer to white supremacists. Facebook is aware of the issue and is asking for ID verification for some affected users.

Facebook told investors in May that it would start verifying the identities of suspected fake accounts.

That verification process is also used on unusually viral material. The platform says the move was an accident but didn’t clarify what caused the slip-up. “We apologize to those affected by this issue,” a Facebook spokesperson told Engadget. “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.”

While the interruption for those affected was brief, it highlights the problem Facebook has with moderation.

The platform has long let overt racists and white supremacists operate on the platform. Perhaps most controversially, Mark Zuckerberg famously refuses to censor anything from Donald Trump – a decision that is costing him engineers.

One search of Facebook Groups will turn up pro-Nazi groups, xenophobic groups, and other hate-mongering. While Both Twitter and Facebook have committed to stopping hate and misinformation on the platform, Facebook’s efforts are tepid at best.

Fighting racism and hate speech online isn’t an exact science, of course. But if Facebook can ban a Led Zeppelin album for featuring butt cracks, it should be able to ban the Nazi flag.