The application doesn't seem to have any cruel overtones - it's more tongue-in-cheek than anything else. You can add George W Bush or Mark Zuckerberg for example. But what is REALLY amusing about EnemyBook is that you can specify why a particular person is your enemy. So you can choose from options like "He killed my family" or "she insulted my honour" or just a straight-forward "I don't know this enemy but I hate them already"!

You can even tell your Facebook contacts to make your enemy their enemy, and if that wasn't enough, you can flip the finger at your enemy!

This one's a keeper for me.