What precisely are you upset about? I did not work on this feature, but I'm trying to understand your reaction.
Your friends entered their phone numbers. They are your friends. You can see those phone numbers if they choose to allow you to do so. You also (possibly) chose to import your address book of your friends and Facebook is showing them to you. The numbers are not public and everyone involved explicitly agreed to share the information. What part of that do you object to?
On further thought, it's possible I jumped the gun on this and that my phone contacts weren't actually taken without consent- my memory is imperfect.
That said, my opinion on facebook's attitude towards me and my privacy is unchanged. It's easy to get jumpy when a company disregards your privacy at every turn. Had this been on google (for example), I'm pretty sure I would not have jumped so quickly to what was probably an incorrect conclusion. But it was fb, who has repeatedly disregarded my wishes and abused my trust to the point where I literally treat everything I put on it as public.
There are phone numbers in that list of people who aren't on Facebook, and given Facebook's relationship with law enforcement, I'd rather they not have them. I understood the Facebook app to be syncing information with people who were already on Facebook, not my entire phone book.
Your friends entered their phone numbers. They are your friends. You can see those phone numbers if they choose to allow you to do so. You also (possibly) chose to import your address book of your friends and Facebook is showing them to you. The numbers are not public and everyone involved explicitly agreed to share the information. What part of that do you object to?