I have no mercy for them. I have no explanation other than pure evil for the thing which i describe below - happy to hear other thoughts on this.
1) On mobile Chrome, in a not private tab, I flag an ad served via the FB ad network, to be precise it was on imgur.
2) On my smartphone, I strictly and only use FB with https://mbasic.facebook.com in mobile Chrome in a private tab. I never logged in in the not private tab.
3) I log-in to FB in the private tab a couple of minutes later and I get a notification that they received and reviewed the complaint from 1)
That was a huge WTF moment for me yesterday - I would love to learn on how they do it and why they think that's something the user would be happy to experience.