> I was wondering if anyone knew a way to block access > to anonymous proxying sites. Some of our users have > worked out how to bypass the denied.list and as a > result we have no logging as to their surfing > activity Yep, proxies are a _huge_ problem. There are thousands of them: my personal list exceeded 10,000 a few days ago, and my blacklist subscription also lists over 10,000. And they keep changing their name every few days. Shady owners can make a small but positive amount of money from every proxy (apparently through showing ads). So every Tom Dick and Harry creates one or two and adds their bit to the giant shell game of "guess where the proxies are". And you're only seeing "most" of it. There are certain technical tricks that will make a proxy completely invisible so you won't even realize you're not seeing the surfing activity history. There are even services that will email a user the "new proxy of the day" every morning. A user opens up their email, plugs the address into their web browser, and voila you've been painted as the fool once again. Depending on how serious you are about fighting proxies, you'll need a good AUP (Acceptable Use Policy), administrative backing, a lot of aspirin, an hour every day, script writing skills, and a combination of Squid and DansGuardian. The combination of Squid and DansGuardian is the only technical approach I know of that works very well - DansGuardian pre-scans the _content_ of every site and ultimate site, so it will block a lot of proxy use even though you haven't yet configured the exact current name of the proxy. The list on http://proxy.org is the most complete one I know of. If you can figure out a way to automatically suck up their entire list _every_day_, remove duplicates, and add all those to your banned list, you can stop _much_ (but not anywhere near _all_) of the illicit activity. good luck! -Chuck Kollars ____________________________________________________________________________________ Shape Yahoo! in your own image. Join our Network Research Panel today! http://surveylink.yahoo.com/gmrs/yahoo_panel_invite.asp?a=7
