anonymous remailers

C'punks -- When I told a friend about the alt.drugs.pot cultivation newsgroup and suggested that he use an anonymous remailer to post to the group, he laughed and said, "Who do you suppose runs the remailers? ATF, FBI, DEA, that's who!" Gee, it makes sense to this paranoid. Does anyone know the answer? Specifically, how can we choose a trusted remailer? Cheers (?), Charley