A cleared sites list includes one or more hostname descriptors. A firewall includes rules associated with a cleared IP list including cleared IP addresses, and permits transfer of a cleared HTTP request from a user device to a cleared destination IP address that matches one of the cleared IP addresses. A controller examines a non-cleared HTTP request from the user device to a non-cleared destination IP address that does not match one of the cleared IP addresses, and acts as a transparent proxy between the user device and the non-cleared destination IP address when a destination host header of the non-cleared HTTP request matches a hostname descriptor of the cleared sites list. The controller further acts as a transparent proxy between the user device and the non-cleared destination IP address when a referrer header of the non-cleared HTTP request matches a hostname descriptor of the cleared sites list.