Them by Jon Ronson

Them: Adventures with Extremists is a romp into the heart of darkness involving 12-foot lizard-men, PR-conscious Ku Klux Klansmen, Ian Paisley, Hollywood limousines, the legend of Ruby Ridge, Noam Chomsky, a harem of kidnapped sex slaves, David Icke, and Nicolae Ceausescu's shoes. While Jon Ronson attemps to locate the secret room, he is chased by men in dark glasses, unmasked as a Jew in the middle of a Jihad training camp, and witnesses CEOs and leading politicians undertake a bizarre pagan owl ritual in the forests of Northern California. He also learns some alarming things about the looking-glass world of them and us. Are the extremists right? Or has he become one of Them? This is a fascinating investigation into extremists of every stripe.

I thought this sounded interesting. It kinda was. I dunno, it's not an easy read. Some bits I found more interesting than others. Needless to say there are some people with some very strange beliefs in the world.