A national trade group representing the digital advertising industry has advised member companies to put stricter controls on consumer mobile-phone location data they provide to government units such as public health authorities and law-enforcement and intelligence agencies.

The Network Advertising Initiative on Tuesday released a new set of best-practices recommendations designed to address the growing use of consumer location data by government entities, advising advertising companies to prevent governments from trying to identify individuals in such data sets as a condition of providing the data.

NAI, which has more than 100 member companies in the digital advertising industry, also recommended that companies that collect or sell location data drawn from mobile devices should provide more robust consumer disclosure about what their clients intend to do with the data and disclose if law-enforcement or other government entities are buying or using the data.

... NAI’s new guidelines are only advisory, however they represent one of the first industry efforts to grapple with the privacy implications of government acquisition of consumer location data drawn from cellphones.

... The advertising industry collects the locations of millions of U.S. cellphones daily. Typically, an individual user is represented only by an alphanumeric string in those databases—with location records not linked to their name, phone number or other personal information. However, in practice, the data is precise enough to reveal intimate details about individual users.