I administer a post-click ad tracking system that serves cookies and tracks post-click activity anonomously. When a specific action page is hit, a web bug is loaded and the cookie retrieved matching creative and reffering site data. I am having descrepencies in stats because of proxy servers sending many users through the same ip address. the system has filters in place that delete repeat actions from the same ip within a five minute time frame which inevetibly screw the stats up. Does anyone have any advice on tracking methods that get around the proxy farm issue?