The European Commission has begun infringement proceedings against the UK over targeted advertising system Phorm.
Phorm's service, which is known as Webwise, tracks users' online surfing habits and then delivers relevant adverts - a practice that's raised a number of concerns from privacy campaigners. But according to the European Commission, it also breaches personal data protection rules.
"Technologies like internet behavioural advertising can be useful for businesses and consumers but they must be used in a way that complies with EU rules. These rules are there to protect the privacy of citizens and must be rigorously enforced by all Member States," said EU Telecoms Commissioner Viviane Reding.
Following a number of complaints from British web users, the commission wrote to the UK government asking to see how EU law was implemented during trials of Phorm's service. However, after looking at the UK's response, Reding revealed she has concerns over in the way the UK has implemented parts of EU rules on the confidentiality of communications.
Reding is calling for UK authorities to ensure they "have proper sanctions at their disposal to enforce EU legislation on the confidentiality of communications".
The Commission has given the government two months to respond. If they feel the response is unsatisfactory, the European Commission may pursue the matter in the European Court of Justice.