The problem is FB and Google has huge reach and steemit has barely a million users. So from an ICO perspective its not a great place yet. I think the ban is not from a ad perspective but trying to stem the obvious fraud in the system. I wouldnt be surprised to see ICO,Wallets and exchanges gets more regulated like the stock market by regulators.Mind that public money is involved and they have a role to play. Wild west of crypto is over!!!!