I wonder if they're like the Bourbaki group in mathematics – an anonymous group where members elect other members, with a trivial amount of cloak-and-dagger secrecy from the public.
That's exactly so. Many of the groups know each other, have their private comm channels, and select insiders that release things out to the broader public. There's obviously drama around people leaking releases, stealing cracks, etc. Fun little sub-culture!