Of all the deception, trolling, obtrusive and aggressive marketing, and scams on Facebook... They chose to ban crypto-currency adds. As much as i hate adds, and acknowledge that a lot are scams, however, this goes to show how much of a disruptive technology block-chain and decentralization is. Even Facebook's business model is threatened.
HYPOCRISY at its best if you ask me.....

Who is Facebook to decide which one is legit and which one is not, and what is the criteria... so much work to be fully transparent about that. Fake news, and regular scams are much easier for them to ban/control and they are not doing that... Suddenly they are worried people can be scammed out of their life savings.
What about sketchy trading platforms, loan ads, and misleading product ads.

This space should either be completely free for everyone to post anything, or regulated on an established and published criteria. Not manipulated trends and payed/sponsored propaganda.
That is my personal opinion. i may be right, i may be wrong.... only the future will tell if Facebook and other centralized models will be able to sustain themselves in the new decentralized economy..... having said that, i would not rule out the possibility that Facebook can become tokenized in the future; but decentralized: i think not.

Too much power in the hands of one person/group/company, corrupts even the best minds.

https://www.theverge.com/2018/1/30/16951670/facebook-cryptocurrency-bitcoin-ico-deceptive-marketing-ban