A rule-based selection, storage and access method and system for processing packets from network traffic. First, packet intercepted from network traffic are selected based on at least one rule. Second, the selected packets are stored in an in-kernel storage buffer, which can be tuned to a size that is appropriate to the number packets being captured and the ability of a packet usage application (e.g., a billing program) to process the packets. Third, an access mechanism is provided to a packet usage application for accessing the stored packets. The intercepted network traffic is provided to a receiving application.