Furthermore, you are alerted of any tagging and you can choose to untag.
Some of us choose to keep the photos where we look sunburned and drunk tagged. Some of us untag everything that's not pristine. What's nice about Facebook is they make it easy to play it either way.
Wouldn't it be better to stay tagged? If you are tagged you can set privacy settings to restrict views on photos tagged of you. Without that the photos are still visible.
It's more a matter of people being able to go to your profile and click a "view photos" link. Some people don't want to restrict privacy, but they don't want drunken pictures on their profile. In the event that my boss looks at me on Facebook, he won't go searching through friends' photos looking for things I untagged.
If Facebook exposes your account information to everyone when your friends tag you in their photos, and you have tagged photos set private, that's a definite leak of data.
However, if memory serves, Facebook does not link back to your account if friends tag you in their photos, and you have tagged photos marked as private.
I may misunderstand your problem, but I fail to see where Facebook is leaking any information.
This is what happened to me when I first signed up for Facebook. Even never having had an account with them in my life, 3 pages in to the signup it popped up a photo of my face and asked me if I wanted to set that as my profile photo. I left immediately and have never returned. I know that whatever I do online is a matter of public record, but it still creeped me out to the extreme.