Who profited from it? What does it matter who profited from it? Should we punish anyone who got paid to rebuild the site? Should we arrest the security officials at airports who were hired do to the attacks?

Obviously, I'm being ridiculous, but just because someoen profits from a tragedy doesn't make them guilty of anything.

Who planned it? We've already established that it was Al Quaida. Bin Laden and Mohamed Atta. And obviously, everyone who carried it out went up in a fireball with the planes, so it's not like we can punish them.