The five Facebook groups that Jeremy Corbyn belonged to - A question that I think deserves an answer

If the five suspect Facebook groups that Jeremy Corbyn belonged to were not antisemitic groups, or groups tolerant of antisemitic sentiments, then why were any anti Semitic posts not removed from the groups by their moderator or moderators?

So which journalist or  interviewer is going to ask Jeremy Corbyn that question? I suggest that it won't be anyone from the BBC.