This is a good move by facebook and does have the potential to save lives, but the fact that they don't provide any details about the attack or the supposed attacker definitely makes it significantly harder for potential victims to act on this information.<p>Imagine getting a message like this out of the blue, not even knowing who's after you. What are you going to do?<p>It's hard to fight a faceless enemy, especially when you can't even be sure if they really exist.