1. A method for responsively varying access to a plurality of content units, the method comprising: providing a digital rights management (DRM) system, wherein the DRM system includes one or more servers, the DRM system controlling access to each of the plurality of content units, the access responsive to at least one environmental condition relating to at least one condition external to the DRM system; receiving a request to access one of the plurality of content units from a requesting computer system via a network connection, the at least one environmental condition being based on a different content unit from the requested one of the plurality of content units; evaluating, by the one or more servers of the DRM system, the at least one environmental condition; adaptively adjusting, by the one or more servers of the DRM system, a protection level of the requested one of the plurality of content units automatically based on the evaluating the at least one environmental condition; and providing, by the DRM system, access to the requested content unit to the requesting computer system via the network connection without requiring the requesting computer system to modify its operating system, wherein the access is restricted based upon the adjusted protection level, the adjusting the protection level being performed prior to the providing access to the requested content via the network connection.