alt.interoperability.adversarial
Important article by Cory Doctorow about "adversarial interoperability" - the concept of building a system that interoperates with an existing system for the purposes of competing with it—what it is, why it matters, and what's happened to it.
In short: alt. took over from Usenet in a way that federated social networks are struggling to take over from facebook and twitter.
(via... I can't remember; EFF's newsletter, probably)