With a little white wine and you'll never even know you are caught until it's too late.

So is Facebook not in its right to change anything at any time for any reason?

Because that's how they've always behaved.

There's nothing more personal than the identity with which you signed up with. Now they get in the middle of all the links that you post and people click on AND all the email that gets sent. My facebook email is nothing more than a namespace reservation, not my primary contact. They've essentially changed my primary contact without my permission.