The City of Los Angeles is spearheading a new private-to-public pipeline for location data. The Mobility Data Specification (known popularly by its acronym, MDS) standardizes data collected by ride share and micromobility providers to make bulk collection and analysis easy. Los Angeles requires all e-scooter providers in the city to disclose individual trip data via MDS. Ostensibly, this sensitive location data is being used to inform certain traffic and curbside policies. But the data could also be used to surveil individuals by re-identifying them through their unique travel paths.
Los Angeles residents, backed by the Electronic Frontier Foundation and the ACLU, sued the city to stop its collection of individual trips data, arguing that the collection violates the Fourth Amendment. The trial court dismissed the case, finding that there was no privacy interest in the location data disclosed to the city, and that even if there were, several exceptions to the Fourth Amendment would apply. LA residents appealed the case to the Ninth Circuit.
EPIC and the Center for Democracy & Technology teamed up to support the LA residents’ appeal. The amicus brief highlights the privacy concerns with MDS, the anticipated expansion of MDS use to other mobility data sources, such as Uber and Lyft, and the surveillance dangers of the overall “smart city” movement. The brief closes with a look at alternatives to bulk individual data collection, such as aggregation, sampling, and differential privacy, all of which are used to analyze mobility data in other contexts and are more protective of privacy than disclosing the individualized data.
United States Court of Appeals for the Ninth Circuit (No. 21-55285)