Two letters from the Center for Democracy and Technology, one to the Washington DC Department of Transportation (DDOT) and the other to the Los Angeles Department of Transportation, raising privacy issues and concerns with data provided using the Mobility Data Specification (MDS).

The first letter 1  cites the U.S. Supreme Court’s finding that time-stamped location data “provides an intimate window into a person’s life, revealing not only his particular movements, but through them his ‘familial, political, professional, religious, and sexual associations.’” It urges that DDOT meet its needs for planning data using aggregated data.

The second letter 1  acknowledges LADOT’s recognition that the data collected via MDS should be classified as “confidential” data under the City’s Information Handling Guidelines but calls on LADOT to be more specific into how the data will be safeguarded, including data retention policies, the uses that will be made for the data, and how access will be controlled. 

The letter cites specific examples, with references, on how confidential location-specific data can and have been misused and explains why the trip data raises serious privacy concerns. The letter then lays out specific privacy policy recommendations for the city to consider.