Black Unicorn writes very persuasively about the problems a remailer operator could face in court:

Mr. Smith, do you charge for users of the remailer? So is it safe to say that you don't intent to profit from this service? Then your motivation for running the service is... to help people destroy evidence then? Ok, sorry your honor, withdrawn. Then your motivation for running this service is definitely not for profit? You're a good citizen, as it were? Yes, of course you are. You destroy all logs about users of the service, isn't that correct? Excuse me, you "fail to record" any information about users of the service? I'm confused. Someone sends an electronic mail to your service, it has a "reply to" or a "from" header on it when it arrives, correct? But before sending it on to its destination, you destroy this information, correct? Excuse me. Delete it. Whatever. I see. So people would use this service to mask their identity, if they didn't want to be responsible for the content they are sending perhaps? And someone committing a crime, something untraceable, they would be able to hide behind your service wouldn't they? But that is a risk of running the service yes? What about, say a drug deal? A death threat? Something libelous? So wouldn't it be safe to say that a reasonable person might expect some abuse of such a service by criminals? Isn't it true that you have an abuse@blah.net address to deal with this precise eventuality? So you expected there might be legal problems? blah blah blah

Most of the replies have missed or evaded his points, relying on classic stubborn cypherpunk libertarianism. "I don't got to justify nuttin' I do, screw you officer." Or the whiny, "But Microsoft does it, why can't I???" BU points out that you DO have to justify what you do, like it or not, and that Microsoft DID get in trouble for these practices. The point which has not been made clearly is that despite the legal arguments against remailers which BU raises above, there are strong legal arguments in favor of remailers as well. It is these positive arguments which we must rely on in a legal context. Head in the sand libertarianism won't help. Remailers exist to provide for the possibility of anonymous communication in a medium where it is otherwise impossible. They are an attempt to extend the status quo for other forms of communication into electronic mail. The do not introduce new challenges or threats into society. Rather, they preserve existing capabilities as we move into a new medium of communication. Due to its technical nature, electronic mail is inherently traceable. Every step in the communication involves recording where the message came from. This allows the mail to be traced back to its source. Remailers exist solely to remove this traceability and to therefore provide for anonymous communication in the medium of electronic mail. Anonymous communication exists and has always existed in many other forms. Postal mail, physical delivery of anonymous notes, posting handbills, passing out leaflets, all have been traditional methods for propagating information anonymously. Every one of the bad consequences of anonymity listed above exists with these other forms of anonymous communications. Terrorists, blackmailers, criminals of all stripes use the postal service. Anonymous publication of unpopular political arguments has occured since the founding days of this country. Anonymity is nothing new in the world. Courts have consistently declared that anonymous speech is a protected right. See for example the 1995 U.S. Supreme Court case McIntyre vs Ohio, http://www.eff.org/Legal/Cases/mcintyre_v_ohio.decision, which relies on Talley v. California, 362 U. S. 60 (1960). By providing anonymity in a medium where it would otherwise not be present, remailers join technologies which "have played an important role in the progress of mankind" (quoting the Talley decision). Any legal action against a remailer would attract interest from scholars and political groups all over the net. First amendment experts, free speech experts, civil liberties groups, all will support the remailer with arguments and briefs. Chances are that financial support will be available as well. BU's "gray haired Reagan appointee" judge is going to be operating in a fishbowl of media attention and legal advice. He needs to be very careful to stick to the legalities knowing that any decision against the remailer will be appealed and backed up by the many interest groups who will be watching the case. These are the kinds of issues which any defense of a remailer will need to rely on in the courtroom. Cypherpunk attitudes of "I don't need to keep no stinkin' logs if I don't feel like it," won't go far. It's a legal and political issue and that is how the battle must be fought.