Why not investigate hatemonger Fred Phelps?

In light of the recent investigations on the Word of Faith ministers (Creflo Dollar, Joyce Meyer, Kenneth Copeland, etc) why won't they also investigate Fred Phelps, the creator of the website www.godhatesfags.com? If you ask me, this psycho is a LOT more dangerous than the Word of Faith camp. Why don't they try to find out what the heck this nut is up to?