BT today kicks off a new trial of Phorm, the controversial web advertising scheme.
Under BT's trial, a small percentage of BT Total Broadband customers will be invited to try the service through a web page that will appear as soon as they open their browser. The web page will also offer users the chance to switch the service on or off.
Phorm has come under heavy criticism from the European Union, which questioned whether it broke data privacy rules. But earlier this month, the UK's Department for Business Enterprise and Regulatory Reform said the system is legal, providing certain safeguards are in place.
BT had reportedly conducted "secret" trials of the system last year, but the police announced this month they would not pursue charges against the company.
According to BT, the free service "increases protection against online fraud and makes ads that appear on participating websites more relevant to your interests".
The telecommunications company will monitor the online activities of around 10,000 customers in the trial, although it hasn't released details of when Phorm will be rolled out to all customers.
Virgin Media and Carphone Warehouse have also announced they trial the technology, although they have yet to confirm a date.