FB should really be doing a bit more review when displaying popular websites - flag them for quick further review. For instance, how many legit CNN accounts do they have?
But this seems to be the norm. Google displays highly misleading ads, especially on mobile. I see fake virus scans, "fix battery issues" and other junk. Google's main search ads had malware downloads, even for popular things like Skype. (And Chrome?)
Microsoft's store had many misleading apps, including fake Netflix apps. It took several interactions between MS and Netflix to get that sorted, and MS still ran fake apps (paid!) for popular software and movies. MS wouldn't even deal with ISVs that complained. Hell, the Windows Store even carried a fake version of Windows at one point! They didn't (don't) verify any details, such as publisher name. For a while, typing "Facebook" into the Start Menu brought up a fake FB app. This should put W10's invasiveness into new light: MS is not competent when it comes to this kind of stuff.
I do wonder how much money this stuff brings in. Is it a significant percent of business for these companies? It can't just be simple incompetence -- in MS's case, they sometimes paid for the junk apps.
I'm still sort of surprised that this junk can make enough money for people to advertise it though. Guess even 20 years after the net started getting popular, there's still enough unsavvy people to scam.