While the world and its dog are rushing to avoid advertising serving technology, British Telecom is trailing Phorm again.

Phorm's technology, which BT will use under the brand of "Webwise," has attracted protests from peers, politicians, technologists and think tanks, who have expressed concerns over legal and privacy issues.

Phorm is currently being investigated by the European Commission. Phorm gives a user a unique identifier, through which the user's browsing habits are observed so as to target advertisements at them. BT said that more than 10,000 punters will be asked if they want to opt into the trial when they commence their browsing session.