institutionalized bigotries

This would be an example of institutional antisemitism. Facebook isn't staffed by Holocaust deniers, certainly, but their responses to Denial go beyond inadequate.

Btw, I checked Newsvine. They seem to have instituted a policy that to accuse anyone of being antisemitic or Islamophobic is against their terms of service. As for actual antisemitism or Islamophobia, I'm sure it's still allowed.