Here’s the text of the memo to the Phorm administrators:

The Wikimedia Foundation requests that our web sites including
Wikipedia.org and all related domains be excluded from scanning by the
Phorm / BT Webwise system, as we consider the scanning and profiling of
our visitors’ behavior by a third party to be an infringement on their
privacy.

Good stuff. This suggests a tactic for a flash-mob operation. If millions of domain owners emailed website-exclusion@webwise.com with demands that their domains be excluded it might have an interesting effect.

Interesting to see that Amazon has already opted out.

Interesting also to see that info about opting out is pretty deeply buried on the BT Webwise site. The relevant para says:

How can I remain opted-out of BT Webwise even if I delete cookies regularly?

We provide the facility to block cookies permanently from BT Webwise so if you want to opt out permanently you can do so through a one-time only activity, by setting your browser to block cookies from the domain webwise.net. When you block this domain, the service will not put a cookie on your machine and you will not be asked to opt in or out again.