Usenet is a public space. Sure, people have attempted to moderate parts of it, but all they've really done is split off from the public space to form private spaces which have restrictive policies on content.
Any forum which captures the desirable qualities of a public space will therefore have to restrict content in some way. The trick is not to restrict content too much, and to make sure the restrictions cut broadly across opinion boundaries.
First of all, I'd like to see remailer servers running on a well-known port. That way, anyone could stick up a remailer, provided they had access to a C compiler.
The problem with a well known port is that it restricts remailers to one per machine. Then in fact only one person per machine could set up a remailer. This does make a difference, because the sysadmin is not the only one technically able to monitor the remailer; its operator is also able. A pseudonymous service, like a pseudonymous person, should not need to be linked to any particular machine except during an actual transaction. If I have a pseudonym, I can post from anywhere and my identity is communicated by a signature. Likewise should a pseudonymous service be able to hop from machine to machine. The techniques of location-independent computing, developed for radio links, can be applied here. What we need is a name service which has public keys as identities and which can map virtual and pseudonymous services to various combinations of IP address, port number, and protocols. In the decentralized spirit, this name service should not have a root. Someone Saturday mentioned that there was a paper from some Plan 9 folk about rootlessness; pointers will be welcome. Eric