1. A method of controlling document access using centrally managed rules, the method comprising the computer-implemented steps of: receiving a plurality of rules at a client system from a central rule database, wherein the rules contain at least one expression used by the client system to perform access control for documents accessed by the client system; detecting a document access operation attempted by an application program on the client system, and evaluating at least one rule from the plurality of rules that pertains to the document being accessed, wherein the evaluating step allows access to the document based on the evaluated at least one rule pertaining to the document.