...it sounds like what you want is a search engine that returns actual data...

...at first read it sounds like you want all of this to be done manually?

No. The idea is that information providers (commercial or otherwise) register themselves as responders. Doing this, they would provide an IP/port combination that would respond to the knowledge protocol; and to those query subjects for which they have registered.

It is up to each information provider to perform the searching of their site only (thought this might be contracted out), in response to the query and return the information requested.

The distributed database I mentioned would only contain the registration database, kill-list information, maybe even a information provider rating system, but no actual information vis-a-vis answers to queries.

All the information delivered by the protocol would be supplied by the information providers in response to queries. If they don't want to release the information into the public domain, they simply do not provide it--and their rating/kill-list position should quickly reflect the fidelity of their responses.

The process would be automated, and probably not be email-based.