End friendship, total disownment of anything having to do with the person.
i looked it up google, my goodness its a group wanting to legalize pedofilia.
how can a group like that be legal?
Technically it falls under free speech here in the States, so there isn't much law enforcement can do, they just watch, and try to catch any members actively engaged in child molestation or similar. Also for many years, they tied themselves in with the gay rights movement which offered them a bit of protection. All the mainstream gay organizations have cut ties with them in the last couple of decades, so they no longer receive any sort of support.
This was a good documentary on the subject and all the legal things surrounding it -
http://www.imdb.com/title/tt0109410/ and I think you can find it on youtube.