Just to make sure that I understand, it encrypts at the server end and decrypts at the client end, right? So no one in-between can see the content, even your ISP?
BTW, here's the blurb from the site:
"...256-bit SSL encrypted Usenet functionality will require a Giganews SSL enabled account. Encrypted authentication, compressed headers, and NNTP commands are available to every customer regardless of whether 256-bit SSL is enabled on their account."