The privacy and security challenges posed by tracking individual vehicles are exacerbated when that information is shared with others.

In Los Angeles, where transportation officials are setting MDS standards, the city has already shared MDS data with private software companies and, in some cases, without placing limitations on its commercial use. City officials have also acknowledged that “some form of the data will be shared with other city agencies.”

These concerns take on particular sensitivity when it comes to sharing people’s location data with law enforcement. Federal immigration and tax authorities have already attempted to identify and track suspects with location data. And in 2016, the Associated Press reported that law enforcement officers across the country abused police databases “to get information on romantic partners, business associates, neighbors, journalists and others.”

LADOT has said, “law enforcement will not have access to raw trip data other than as required by law, such as by a court order, subpoena, or other legal process.” But former Los Angeles Assemblyman Mike Gatto, who chaired the Consumer Protection & Privacy Committee, warned that when government agencies create public databases, “law enforcement has the ability to access it, and they will.”

The Center for Democracy and Technology has also pointed out that MDS could become “a barrier to entry for low-income and minority riders, who already face disproportionate surveillance from law enforcement and other authorities. Without appropriate safeguards restricting access to the data, its collection could deter underserved riders.”