Data files are distributed across a plurality of computers. The computers may
form a network such as a content delivery network (CDN) or a peer-to-peer network.
The network may operate as a TCP/IP network such as the Internet. Data files may
represent may represent digital messages, images, videos or audio signals. For
content-data items or files in the system-a name is obtained (or determined), where
the name is based, at least in part, on a given function of the data in a data
item or file. The given function may be a message digest or hash function, and
it may be MD4, MD5, and SHA. A cony of a requested file is only provided to licensed
(or authorized) parties. The system may check one or more computers for unauthorized
or unlicensed content. Content is served based on a measure of availability of servers.
