The history of the Internet is in part a history of the dismantling of the music industry. From the moment that someone first figured out that music tracks could be converted from the gentle but warm hiss of analog to the precise but chilly efficiency of digital, the recording industry's days have been numbered. Even putting aside, temporarily, the rampant theft of intellectual property that the Internet has facilitated, there was a certain economic inevitability to consumer preference for a music delivery mechanism orders of magnitude cheaper and faster than distribution through LPs, cassettes, and CDs.

But of course, there has in fact been rampant intellectual property theft on the Internet, virtually from the moment that the .alt newsgroups were added to Usenet (one wag described the newsgroup "alt.sex," widely used to share low-res scans of Playboy and Penthouse pictorials, as "gigabytes and gigabytes of copyright violations"). In an effort to buy time while they figure out a new business model, the record companies have lobbed attorneys at any infringing target they can find. Napster, the inventor of peer-to-peer file exchange, was the first to fall, lasting just over two years before being shut down by court order. Most recently, the Recording Industry Association of America secured another major legal victory when U.S. District Court Judge Kimba Wood last month ordered the shutdown of the popular peer-to-peer client LimeWire, which she found was actively encouraging the search for and downloading of copyrighted music files shared across the Gnutella network. (Gnutella is one of a number of peer-to-peer networks for content distribution operating over the Internet; other examples include Skype [voice over IP], BOINC [scientific data], instant messaging, and even the Domain Name System [Web site information]).

Many if not most computer forensics specialists have run across LimeWire, but only rarely in the context of music infringement. There's a darker side to LimeWire/Gnutella, one that has been largely ignored in the coverage of the RIAA's lawsuit: Its widespread use as a tool for the distribution and downloading of child pornography. Since any type of file can be distributed across the Gnutella network, numerous individuals use it to distribute photos and videos of children engaged in sexual activity. Some post the images as advertisements for ephemeral for-profit child pornography Web sites, others do so to garner attention from and exchange content with other child pornographers, and some do so out of sheer ignorance.

Due in large part to Gnutella and LimeWire, the problem of child pornography has exploded in recent years. The ready availability of digital camera technology, combined with the Internet and peer-to-peer networks, has made it extraordinarily easy to produce and distribute contraband images. But peer-to-peer technology is a double-edged sword: the same networks and software that have eased the distribution of child pornography have also given law enforcement powerful new tools for locating and tracking perpetrators.