I already did read the article and I did not get that impression. If it's really that small and private, why mamke a website about it for friends and prospective members? Why architecture the network in a way that favors scaling, including mulitple backbone nodes running diverse software with the option to add more? Clearly these indicate thats it's not that small or exclusive. I would bet that if you were to bump into someone at DEF CON and they were a member, all you'd have to do to join is say "that's so cool, how can I join".