Libernet was a libertarian e-mail discussion list that started some time in the 1980s, and ran at least through much of the 1990s. It was one of the most popular online libertarian channels prior to the rise of Yahoo groups and other "social media".
Libernet started prior to the availability of commercial e-mail list service providers (e.g. Yahoo groups), or even standard e-mail list software (e.g., Mailman). So it was originally just an e-mail forwarder on a computer to which the list operator had access. People who wanted to join or leave would simply send him a request by e-mail, and he would change the forwarding table accordingly.
Interconnection with LIBERTY Echo
For most of the time that it existed, the Libernet mailing was bidirectionally linked with the LIBERTY "echo" on Fidonet, through a gateway operated by Joe Dehn. This allowed users of any of the Fidonet bulletin board systems (BBSs) on which LIBERTY was available, many of whom did not have access to Internet e-mail, to participate in a discussion forum together with the people who did have direct Internet access (e.g., through a university computer system).