Darknets have been on the increase for some time, but as they get ever simpler to use and deploy, they could make it more difficult for content industry investigators to gather data for use in court cases or for "graduated response" schemes with ISPs. Massive darknets can be infiltrated, but networks of 10 friends? 20 friends? An extended family? It will be nearly impossible to know what's being transferred there.I've been hearing about darknets since around 2005 and never thought of them as a threat to creative folks. They're far more analogous to how people used to share and explore music before file sharing - a group of people with common interests share what they have. As I've discussed plenty before, my friends and I will often burn CDs for one another whenever we get a new album. And no, the recipient of the burned disc oftentimes doesn't go out and buy that same record again. However, if they like the music, they will most certainly buy the next album. They will also spread the word to others, who will buy the album.
I doubt anyone in the industry would (legitimately) argue that an individual burning a CD for a friend is a bad thing. Consumer 1 buys Record A and burns for Consumer 2. Consumer 2 buys Record B and burns for Consumer 1. It all works out in the end, so long as Consumers 1 and 2 don't then make their purchased records available to Consumers 3 through 6,000,000 on an open p2p site.
So should the labels be concerned about darknets, especially those consisting of 10-20 people? No way. They may be virtually impossible to infiltrate but there's no reason to; groups of that size are intimate and replicate what people do in the real world. If the group gets large and impersonal, thereby creating a microcosm of what's on large file sharing networks, then the darknet isn't so dark. The larger a group gets, the easier it is to find, thus making it easier to break up. In other words, there is a direct correlation between the ability to break up a darknet and the need to do so.
As to any concerns about college campuses and the likelihood of a collection of students forming a darknet that's big enough to make an impact - labels are already working towards creating paid, open file-sharing options at various schools. If you can get every song you want for free through a user-friendly interface, why worry about digging through the tens or hundreds of individual collections of your classmates?
Labels should keep their eyes fixed on large-scale infringers; those who are making money off of the free distribution of others' work or making it available on a mass scale. Darknets only mimic what people do ordinarily and, if anything, are a great viral marketing tool to help sell more records.