One of the consequences might be that if you say a lie about someone else, they will sue you for libel. And in an ideal world, the lie would be discovered and you'd lose that suit. So asking a user on facebook to remove a lie, then asking facebook to remove that lie, sounds like a fair thing to do in a "real" democracy.

> Governments should not have the power to silence their critics

I agree completely, but we are talking about the case when they are trying to silence a lie. That's different than critics.