The Commission has opened an infringement proceeding against the United Kingdom after a series of complaints by UK internet users, and extensive communication of the Commission with UK authorities, about the use of a behavioural advertising technology known as ‘Phorm' by internet service providers. The proceeding addresses several problems with the UK's implementation of EU ePrivacy and personal data protection rules, under which EU countries must ensure, among other things, the confidentiality of communications by prohibiting interception and surveillance without the user's consent. These problems emerged during the Commission’s inquiry into the UK authorities’ action in response to complaints from internet users concerning Phorm.