Just seen on BT's BETA forum Miles Golding's post;
BT's legal department has written to ask for my website URL(s) and confirmation of ownership, without which they will not be able to honour my request to refrain from interfering with code and scanning/logging data exchange bewteen my site(s) and visitors' computers. If I do not provide the information, they do not consider themselves to be under an obligation to pro-actively check websites to ascertain if they contain 'opt-out' wording, and are confident that this position is compatible with the relevant legislation.
Three things.
One, that's an admission of copyright liability.
Two, you are under no obligation to make their system legal.
Three, they are obliged to obtain your consent before copying your work.
Miles if you're reading, can you post a scan/the text of their correspondance?