Facebook didn't respond immediately to a request for comment.
'Facebook didn't respond' - is closer to reality. Facebook CEO + CTO UK/US repeated testimony of 'I don't know' is all about stalling. Do they still see this as a PR issue, that will just go away, like 15 years of past apologies. Lets have a quick reminder of 'the core values' at Facebook:
https://www.bloomberg.com/news/features/2018-03-27/ad-scammers-need-suckers-and-facebook-helps-find-them