The new version of P2P client LimeWire—now at version 5.1.1—has been in the news lately for a feature that makes it simple for even the newbiest newb to create a "darknet." Nothing here is technically ground-breaking, but LimeWire's massive install base means that millions of users now have a secure and simple way to share files with each other and no one else.

Darknets are going mainstream, something that could make it more difficult than ever for rights-holders hoping to monitor public P2P networks in order to pick off offenders. That process, already difficult enough, could get a lot harder as such tools migrate out from the geekerati.

Darknet, with a twist of lime



Most P2P networks are open to any client, and it's a trivial matter to find and download content—indeed, this ease of use is the main point. In doing so, the IP addresses of the peers serving the files are revealed. When the content those peers serve infringes copyright, the IP addresses make it possible for rights-holders to file lawsuits.

In darknets, there is no public entry point to the network, making it difficult or impossible to know what's being shared. The very term "darknet" makes the whole process sound mysterious and quite possibly illegal, but such a darknet can just as easily be used by a family to share photos and video content.

The new LimeWire makes this easy. Users can share any file or class of files with only certain buddies. The files are kept updated on all machines, and newly shared files automatically show up on the other machines in the network. It's simple to do this using other services like Dropbox, which allows for group shares. Direct download services like RapidShare have also become popular ways to distribute even gigantic files without putting them on public P2P networks.

But LimeWire already has millions and millions of users, and is one of the most popular P2P clients. It's not yet clear how many casual users would want to use the system to share copyrighted material; hot new releases will require access to public P2P searches unless one happens to be friends with a music business insider. There is also no facility for adding public P2P users as buddies, meaning that you need to know them first.

For college students, though, such a system could make it easy to browse the music collections of everyone on one's floor, even with limited technical skills or familiarity with current darknet systems. Certainly, the new feature is likely to be seen in that light by the music industry, which is already suing LimeWire.

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.

And if graduated response truly takes root around the globe, its biggest achievement might well have little to do with stopping copyright infringement and more to do with driving it deeper underground. Certainly, the simpler the tools become, the more likely is the possibility.