Unfortunately, although PlusNet plan to have nothing to do with Phorm, it seems that BT are still too incompetent to make that feasible. A number of PlusNet customers recently received the invitation page to 'opt-in' to the current BT trial of Phorm, apparently due to a configuration error in the network.

Unfortunately the UK government appears unwilling to make any attempt to stop this. The tinfoil-hat-wearers believe that it's due to the government's desire to get their hands on a similar system for themselves. Personally, I think it's just a case of resounding incompetence.

For info on countermeasures for webmasters, visit Dephormationor PhormCheck or Deny Phorm. There's a lot of material out there if you look for it, this is an issue that most of those in the know are not keen to let lie.

There's been a lot of analysis of the legal implications by people a lot more qualified than I - see e.g. the Foundation for Internet Policy Research analysis, Dr. Richard Clayton's analysis, or the deconstruction of Phorm's own spin at Is Webwise Legal?. At the very least, there are plausible arguments for fraud and computer misuse (the forged cookies that claim to be from the sites you visit, but are inserted by Phorm) and copyright infringement (commercial exploitation of copyrighted content - not by inserting ads into sites that aren't signed up to Phorm, but by scraping those sites and converting them into advertising profiles, regardless of the site's copyright license / usage terms). Note that most of the data protection issues are generally covered by the modified terms and conditions that BT get you to sign up to when you 'opt-in' to Phorm. Note further that those terms and conditions can be accepted by anyone in your home, so your kids could sign you up without you realising - and BT are attempting to make that your problem.

In theory, you can opt out your site by banning *all* spidering in robots.txt (*rolls eyes*), or by emailing them and asking to be put on a black list. But you should be aware that when asking to be put on the blacklist, it seems clients from various IP addresses immediately come and spider your entire site - presumably to enable offline profiling of your visitors anyway. Most people deprecate use of site opt-out in this way - it shouldn't be your responsibility to notify Phorm that they don't have a license to use your copyright content in this way, and cooperating with them on this point will just encourage them. However, see PhormCheck or Dephormation for methods to implement a dynamic robots.txt that will just block Phorm, and no other spiders - plus various other countermeasures.