When the Drug Enforcement Administration (DEA) announced plans to position automated license plate cameras along Interstate 15 to identify potential drug traffickers by travel patterns, some state lawmakers were leery of a scheme that could keep motorists’ movements on file for two years.

“From the public relations aspect and the government intrusion into life, I hate this,” Utah Senate President Michael Waddoups (R-Taylorsville) told The Salt Lake Tribune in May. But the DEA already has similar cameras in California and Texas, and is considering locations in Arizona. The drug agency is following in the footsteps of many local police departments, which have quietly installed license plate recognition (LPR) cameras with minimal debate.

A 2010 study from George Mason University’s Center for Evidence-Based Crime Policy found that “over a third of large police agencies have already adopted LPR” with little discussion of its effectiveness or community concerns. The fact that “only 28.5 percent of agencies researched the legal implications of the technology” may explain their widely varying policies for storing and using data.

That disparity could disappear, thanks to Vigilant Video, a Livermore, California, company that offers police the ready-to-use National Vehicle Location Service. California Watch, a nonpartisan online journalism operation funded by the Center for Investigative Reporting, reports that the database is “bulging with more than 550 million license-plate records” obtained from law enforcement agencies and the company’s own 2,000 camera-equipped scout cars.