Following the fallout earlier this year over BT's deployment of the Phorm online targeted advertising technology, a full investigation has finally been launched by police.

The probe follows a July protest at BT's Annual General Meeting at the Barbican, when an anti-Phorm group gathered to show its disapproval at the two trials the telecommunications giant carried out in 2006, supplying Phorm with access to thousands of London BT customers' browsing history without telling them. At the time, reports The Register, BT insisted that the secret trial was entirely legal, even though it appeared to breach wiretapping laws.

Internal documents

In the time since, the protesters have put together a dossier of evidence to try and prove BT's skullduggery that includes the internal documents detailing the 2006 trial itself, which apparently state that the two week operation's specific aim was to track BT's 18,000 London customers without them knowing.

While there's no current indication that formal proceedings will take place, BT has said it took legal advice when running the trials, and was told that it was not breaking the law. Data law experts still apparently maintain that it broke several criminal statutes.

The European Commission continues to pursue its own investigation into Phorm and specifically BT's trials of its technology, so it's not looking good for the communications firm right now.