Comment Free Speech or Free Noise? (Score 3, Insightful) 488
If you want to apply the usual ethics about freedom of speech, you ought to require him to use some form of authentication for his friends, to ensure that their speech is accessable (since he won't be blacklisted) and free of excessive noise (spam, viruses). VPN tunneling, IMAP, shell accounts, webmail, authenticated POP, and POP over SSH come to mind.
Of course, I'm assuming that spam and viruses are not valuable examples of free speech in action, a view that may be difficult to justify. I consider them to not be speech for the same reason that I don't think the signals generated by a garage door opener are speech--they are signals, possibly meaningful in some context, whose intended purpose as used is to cause some event to occur. The spammer says, "I push this button, and our monthly page views go up!"; the virus distributor says, "I push this button, and 3y3 0wnz j00!"; I say, "I push this button, and my garage opens!" In none of these cases is the button pusher trying to convey any information to another person. If the signal (virus, merchandise, scam) is itself an object of conversation, I can see it being speech, but that context isn't relevant to open mail relays.