"In cryptocurrencies, Facebook saw both a threat and an opportunity. They held the promise of disrupting how things are bought and sold by eliminating transaction fees common with credit cards. That comes dangerously close to Facebook’s ad business that influences what is bought and sold. If a competitor like Google or an upstart built a popular coin and could monitor the transactions, they’d learn what people buy and could muscle in on the billions spent on Facebook marketing. Meanwhile, the 1.7 billion people who lack a bank account might choose whoever offers them a financial services alternative as their online identity provider too. That’s another thing Facebook wants to be."