Rugrunner,
The only thing that article says is "the group's attorneys will try to block any attempt by the Curleys to get NAMBLA's membership lists, or other materials identifying members." It says nothing about NAMBLA publishing Kiddie Porn or "how to" books on child rape.
I disagree with NAMBLA and find this group of men appalling. However, they have a constitutionally protected right to have a webpage (they no longer have one by the way) that tells of their beliefs. I've seen their former webpage (don't dig into that too deeply..ha ha, I was doing research for a book), and it had nothing illegal on it. It questioned the laws of statuatory rape, which I find sickening, but the site didn't suggest that people break them. It suggested they fight the laws and try to change them.
The ACLU made attempts to protect the identity of the men who ran this page due to the attempts of the lawyers that were trying to circumvent privacy laws and obtain their identity. Right or wrong, they had a right to privacy and when the law is going to be broken to peek into this privacy, we all suffer the consequences.
In a similar case, the ACLU also defended the writer of the book "Black Death," and the publishers of "The Anarchists Cookbook." a few years back.
The reason that it "seems" that the ACLU is always defending the left, and not the right, is because it's the cases of the "left" that hit the newstand. Defending the rights of flag-burners is always good gossip amongst ACLU haters, but defending the rights of a pastor in VA to pray in public is not good gossip stuff so it doesn't get mentioned.