The 0xdb is a rather unique kind of movie database. It uses a variety of publicly accessible resources, like search engines and file-sharing networks, to automatically collect information about, and actual images and sounds from, a rapidly growing number of movies. What the 0xdb provides is, essentially, full text search within movies, and instant previews of search results.
The core idea behind the 0xdb is that file-sharing networks can not only be used to download digital works, but also to just retrieve information about them. Even though most movies in the 0xdb are copyrighted, and many of them are practically inaccessible for legal reasons, the monitoring of peer-to-peer traffic allows the 0xdb to identify and index these materials.