1. A method of filtering input/output requests of a computer system, the method comprising: (a) receiving a plurality of I/O requests from a filter manager of the computer system, the filter manager executing in the system space of an operating system executing on the computer system; (b) applying a hierarchical rule set to at least a portion of the plurality of I/O requests by a mini-filter executing in the system space of the operating system executing on the computer; (c) providing, as a set of filtered I/O requests, at least one of the plurality of I/O requests from the mini-filter to an agent executing in user space of the operating system in response to the application of the hierarchical rule set by the mini-filter, the agent being operable to associate meta-data with a set of digital assets identified by the set of filtered I/O requests; wherein non-filtered I/O requests are not associated with meta-data by the agent to reduce overall computational load generated by the filter manager, the mini-filter and the agent; and (d) applying, by the agent, another hierarchical rule set to one or more of the received I/O requests to generate at least at portion of a digital asset identification tag for that I/O request; and wherein the agent is further operable to perform an inheritance-based categorization operation on a first digital asset in response to a filtered I/O request of the set of filtered I/O requests from the mini-filter, the inheritance-based categorization operation including application of meta-data identifying same categorization information as that of a second digital asset related to the first digital asset.