You're a grieving family. Your son or daughter has been killed in Iraq. You're aware that he wrote you one last letter on his Yahoo e-mail account, but thought he'd make a few more edits before he hit the send button. In the meantime, though, the letter has to go into the "drafts" box because he has to go out and kill a few evildoers. Unfortunately, the evildoers get him first. Obviously, you want that letter. It's the last thing he thought about as it relates to you and the family. It's something you'll surely cherish for the rest of your life. One more time where he said "I love you" and "I miss you."
But you don't have his password. You call Yahoo. Should be easy, right? Forget it. No password. No letter. Those are the rules.
If reporters can be sent to jail for not giving up their sources, even for stories they didn't work on (i.e., Judith Miller of the New York Times), then Yahoo "should go to jail" for not giving up this letter.