Let's say 1% of all their users is fed up because of this and 0.1% actually closes their account. This leaves Zuckerberg with 98.9% control over e-mail traffic from 900+ million users. Well played, Zuck, well played.
Couldn't this be construed as an abuse of a monopoly(antitrust)? They have a monopoly on social networking(there are alternatives, but they are very very small in comparison) and they are leveraging that to expand massively in another sphere, namely as email providers.
