But to be fair, they've said everyone with a Facebook username gets username@facebook.com. You can visit a profile, look at the URL, and put 2 and 2 together. It'd be worse if it was a randomized, private email address that was made public.
It's one thing to just hide a piece of information a user asked you to publish on their behalf. It's another to remove it, and then replace it with a nearly identical element because it's preferable to you from a business perspective.
The latter is why folks are upset; simply hiding all listed emails, or adding in the @facebook emails on profiles, would probably not have generated as many complaints.
True, but there is a fine line. You cannot reasonably move a product forward if a few select people refuse to play along. Every product I release, I'm met with disdain from users that don't want to change, and how it was perfect the way it was. And the next release with a different change, it's the same users complaining how the version that they're using now is perfect, why would I change things?
People love to complain, and people don't like change.
There is no fine line here. Facebook changed a personal attribute of their users. This particular action is not justifiable under any circumstances I can see.
The only justification i can see is that it's facebook, and this is pretty much the sort of behaviour i expect from facebook. i have a hard time getting outraged over behaviour that is totally in character.
They're ethically obligated to hide infomation users don't want released, but are they really expected to publish everything their users ask to make public? It's annoying, but it doesn't spur anything like the moral outrage I would feel if they publicized your hidden addresses. At worst its a minor inconvenience.
It's less about convenience and more about assuming the ability to modify a primary attribute of one's online identity without advance notice.
People will sit back, be quiet, and move along and Facebook will progressively march forward with the invasion and the general populace will scream about it until it's too late.
I'm not aware of a definition of reasonableness that hinges on the behavior of just "a few select people." To wit: if 100% participation is required, it's not reasonable.