Several approaches to selectively filtering network traffic are described. One approach involves a system for selectively filtering network traffic. The system includes a helper application, which is coupled to a networking program, and is used to identify a user-initiated request. A network filter driver is coupled to the networking program, for intercepting the user-initiated request. A filtering service is coupled to both the helper application and the network filter driver, and is used to determine if the user-initiated request is allowable. If the request is allowable, the filtering service is configured to generate a special identifier, which the helper application is configured to include in a subsequent request. The filtering service is configured to allow a subsequent request which includes the special identifier, and the network filter driver's configured to strip a special identifier from subsequent requests.