A new trojan/virus out called Phatbot has already infected hudreds of thousands of PCs accoprding to a /. blurb. This is the first virus I've noticed (but to be honest I don't spend a lot of time keeping up with virus trends) that uses a darknet for its control architecture:

What sets Phatbot apart from its predecessors is the use of P2P to control the botnet instead of IRC. Although Agobot has a rudimentary P2P system, IRC is still the main control vector. The author(s) of Phatbot chose to abandon Agobot's IRC and P2P implementations altogether and replaced them with code from WASTE, a project created by AOL's Nullsoft division (and subsequently canceled by AOL).

A darknet is a network which has taken pains to protect traffic content via encryption and trusted networks. I disagree with the wordspy definition which reads like Old Media propaganda.

I wrote about WASTE when it came out and turned me on to the possibilities of darknets. I see darknets coupled with social network mechanisms as an answer to many of the woes of the present day Internet.