The Crown Prosecution Service (CPS) has decided not to prosecute BT over its trial of the controversial Phorm behavioural marketing technology because of insufficient evidence.
BT first got into trouble around four years ago when it conducted secret trials of the monitoring system which analyses surfing behaviour so that ISPs can accurately target customers with advertising.
The technology was subsequently dropped by BT, TalkTalk and others, while privacy campaigners raised concerns that its information collecting was too intrusive.
However, the CPS has decided not to prosecute BT for "unlawful interception of internet browsing data" in its unannounced trial.
"We obtained expert evidence to enable us to understand how the technology worked, how many people were affected and how they were affected. Those are the key elements of the alleged offending," said Andrew Hadik, reviewing lawyer for CPS London's Complex Casework Unit.
"Even if further evidence were available and collected, we are satisfied that it could not change our assessment. We have concluded that a prosecution would not be in the public interest."
The CPS said in a blog post that several factors led to its decision not to prosecute, including the fact that BT received a considerable amount of legal advice prior to the first trial. BT had also immediately changed direction when it received warnings against the technology.
The CPS also said that the trial was of limited duration and that there was no evidence to suggest that anyone affected by it suffered any loss or harm.
The CPS decision, however, could yet be challenged by privacy campaigners.
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