Shutting down lunatic web sites just throws this stuff underground, where you can't see what it's doing. That's not good.

Having this stuff openly on the web makes it obvious to most people just how looney they are, and keeps us all aware of the lines of thought that we may have to deal with. For every one person who is attracted to, say, a Nazi organization by reading their Nazi web site, probably hundreds who might never have given the matter much thought otherwise, will be repelled and put on their guard against such ideas.

Making such sites illegal, even assuming such was technically possible on the Net, puts the looneys back into the world of secret basement meetings and rallies, and then the first you see of them is when they are marching down the street. Maybe then it's too late to be put on your guard.

Keep the web open to all. I've got more than enough resources on my end to keep my kids from seeing anything they're not ready for.

An example I suppose of "keeping your friends close, but your enemies closer."