It used to be IRC mainly. Efnet, later Linknet or similar. Often involved the group maintaining their own server linked to the network (preferably hosted by an admin of a big university). The server not only made sure that only encrypted connections were allowed (hi Blowfish), but also that clients authorized to use it automatically received a spoofed IP/hostname (something childish like @i.am.too.leet.for.paradox.org) to hide ones true location.
No comments yet.