The face/mask of Facebook is that they are a platform for sharing, and that FB users 'know' what they are sharing and making public. Users mistakenly assume that is the limit to the personal data that FB collects. I don't know why FB felt a need to go beyond that and start stalking everyone on the internet. They made their choice.

Point being, FB could have focused their data collection on only that information that their user's post.

I removed fb from my phone a while back but have now removed my profile. The whole concept is based on deception