The U.S. Department of Justice has been working on a secret intelligence-gathering program to build a national database and track the movement of millions of cars in the country, the Wall Street Journal reported, adding that the new domestic surveillance program can examine and store hundreds of millions of records about the nation’s motorists.

The major goal of the license-plate tracking program, which is operated by the Drug Enforcement Administration (DEA), is to seize cars, money and other assets to fight drug trafficking. However, the use of the database has been expanded to track and apprehend vehicles linked to other crimes, including kidnapping, killings and rapes, the Journal reported, citing a government document and people familiar with the matter.

“It is not new that the DEA uses the license-plate reader program to arrest criminals and stop the flow of drugs in areas of high trafficking intensity,” a spokesman for the justice department told the Journal, adding that the program complies with federal law.

Although officials had previously said that only vehicles near the Mexican border were tracked to combat drug cartels, it had not been disclosed before that the DEA has been working for years to expand the program’s reach throughout the country, according to the Journal. The report also said that many state and local law-enforcement agencies are currently testing the database for a variety of investigations. However, it is not clear whether the program has been supervised or approved by any court.

Senator Patrick Leahy, the senior Democrat on the Senate Judiciary Committee reportedly criticized the program, saying that it could trigger fear among Americans as their locations and movements would be constantly tracked.

The program “raises significant privacy concerns,” the Journal quoted Leahy as saying. “The fact that this intrusive technology is potentially being used to expand the reach of the government’s asset-forfeiture efforts is of even greater concern.”

The latest report comes after the USA Freedom Act, a bill to limit the NSA’s surveillance practices, failed in November to garner the minimum 60 votes in the U.S. Senate to move forward. The bill did not pass despite support from the House of Representatives, the White House and the NSA.