BT has signed up to using a system called Webwise from a company called Phorm. Once they have finished integrating it with their ISP systems it will intercept and scan all HTTP requests, building up a profile of what you as a user look at online. The system will later use this data on partner websites to send targeted advertising to you.
Virgin and TalkTalk are also looking into using this technology, although they haven’t committed to it yet.
If you run a commercial website selling stuff, Phorm will intercept some of your visitors traffic and will link your products to their profile. The user will then get adverts for your competitors websites. Yes, I am not kidding. Fortunately, as a website administrator you can add your website to their exclusion list by sending an email to email@example.com. See here for further details.
If you run a website, there is no advantage to you of letting Phorm intercept your users traffic. Get yourself excluded!
UPDATE: I sent the following email on the 26th of March:
From: Mike Cardwell <postmaster (at) grepular dot com> To: website-exclusion (at) webwise dot com Date: Thu, 26 Mar 2009 10:26:46 +0000 Subject: grepular.com exclusion Please add my websites to your list of exclusions: grepular.com www.grepular.com grepular.com haven.grepular.com lists.grepular.com If possible, please add all wildcard subdomains of grepular.com, ie *.grepular.com. Please confirm when this has been done. Regards, Mike
And received this response today (6 days later)
From: website-exclusion <website-exclusion (at) phorm dot com> To: <postmaster (at) grepular dot com> Date: Wed, 01 Apr 2009 09:59:48 +0100 Subject: Website Exclusion We have completed your request to exclude the following URLs from the Webwise service: .grepular.com If at any time you wish to have one or more URLs removed from the exclusion list, you may make your request at firstname.lastname@example.org.