The more wealth, the deeper and more heinous one's crimes can be.

It's not that Satoshi would fund a terrorist organization, because I find it unlikely he would do so. But he is just a few clicks away from sending his bitcoins to ISIS, say. And if he did that, wouldn't you want to know who he is?

Law, like programming, is defined by the corner cases. Laws aren't written from the perspective that 99% of people are good. They're written from the perspective that there's 1% who aren't.