§ Norman Baker
To ask the Secretary of State for the Home Department what controls exist to regulate the monitoring of the location of individuals through signals sent by mobile phones. 
§ Mr. Denham
Communications data, including location data, may be supplied voluntarily for specified purposes (e.g. investigation of crime) under the Data Protection Act 1998 and the Telecommunications Act 1984. It may additionally be supplied in obedience to Court Orders.
A new regulatory regime will be provided by Chapter II of Part I of the Regulation of Investigatory Powers Act 2000. This will be brought into force in due course.831W
Under Chapter II, an authorising officer must consider that the communications data are necessary for one of the purposes specified by the Act and that the conduct involved in obtaining them is proportionate to what it seeks to achieve.
Access to communications data will be subject to oversight by the Interception Commissioner.