Gnutella's Architecture

Currently, the most popular system for sharing files is another peer-to-peer network called Gnutella, or the Gnutella network. There are two main similarities between Gnutella and the old Napster:
Users place the files they want to share on their hard disks and make them available to everyone else for downloading in peer-to-peer fashion.
Users run a piece of Gnutella software to connect to the Gnutella network.
There are also two big differences between Gnutella and the old Napster:
There is no central database that knows all of the files available on the Gnutella network. Instead, all of the machines on the network tell each other about available files using a distributed query approach.
There are many different client applications available to access the Gnutella network.
Because of both of these features, it would be difficult for a simple court order to shut Gnutella down. The court would have to find a way to block all Gnutella network traffic at the ISP and the backbone levels of the Internet to stop people from sharing.