Filter for a distributed network

A computer-implemented method operable in a network, said method operable on at least one device comprising hardware including memory and at least one processor, the method comprising:

• (A) responsive to a request relating to a particular file, wherein the particular file refers to or is a website, determining whether or not an identifier for said particular file corresponds to an entry in a database, said database comprising a plurality of file identifiers, and wherein the identifier for said particular file comprises a uniform resource locater (URL) or uniform resource identifier (URI) associated with said website and wherein the request comprises the identifier;
• and
• (B) when the identifier associated with the particular file corresponds to an entry in the database, providing a response, said response being based, at least in part, on information in said database corresponding to said identifier for said particular file, wherein said response comprises an indication of a substitute file distinct from said particular file, wherein the indication of the substitute file comprises a uniform resource locator (URL) or a uniform resource identifier (URI) of the substitute file,
• wherein said network comprises a plurality of indexing nodes, wherein said request was from a particular indexing node of the plurality of indexing nodes, said request being a request for permission for said particular indexing node to index the particular file and wherein the response is provided in (B) to the particular indexing node.