On Wednesday, the American Civil Liberties Union (ACLU) released documents showing that Immigration and Customs Enforcement (ICE) has access to a huge license-plate database that it uses to track and target immigrants.

The ACLU of Northern California obtained the documents through a Freedom of Information Act lawsuit that revealed ICE’s use of a automated license plate reader (ALPR) database operated by a company called Vigilant Solutions.

ALPR systems not only pass on license plate information, but they include time, date, and location from thousands of cameras. The ACLU previously outlined how ALPRs record Americans’ movements and called them an emerging form of mass surveillance.

More than 9,200 ICE employees can use the database, which collects upwards of a hundred million license plates each month. According to the ACLU, ICE itself has over 5 billion data points collected by private businesses — such as insurance companies and parking lots. But, ICE can gain access to 1.5 billion more records collected by law enforcement agencies.

License plates are collected from cities across the United States, including New York and Los Angeles, even though both of those cities have laws limiting police cooperation with ICE, as reported by TechCrunch. One email said law enforcement sharing data makes the system “as easy as adding a friend on your favorite social media platform.”

A report published in the documents said more than 80 law enforcement agencies share license plate locations of residents with ICE. That includes sanctuary cities like Union City, California. The ACLU said, “We do not know whether police gave notice to their residents before agreeing to share years of intimate details with ICE.”

This isn’t the first time people have become aware of ICE using a license plate database. That was originally revealed in early 2018, as reported by The Verge. However, these documents show just how expansive ICE’s tracking is and who else is helping them.

“ICE has long embraced technology to target immigrants,”the ACLU said. “Now it’s taking surveillance to an unprecedented level to target vulnerable communities — and sweeping up everyone else in the process.”

As expected, there aren’t really any privacy protections in place. ICE does have Privacy Guidelines but, as noted by the ACLU, it “contains gaping holes” that allow ICE to “infringe on civil liberties.”

The database gives ICE access to up to five years of driver information. The  ACLU argues that “storing that much location information is both a significant invasion of privacy and entirely unnecessary to find someone’s current location.”

In addition, there are no privacy rules stopping ICE from going after other individuals, increasing the likelihood of “baseless stops and false arrests,” according to the ACLU.

Vasudha Talla, staff attorney with the ACLU of Northern California, told TechCrunch, “The public has a right to know when a government agency — especially an immoral and rogue agency such as ICE — is exploiting a mass surveillance database that is a threat to the privacy and safety of drivers across the United States.”

The ACLU is calling for an end of the database system and urging local governments to take immediate action in order to protect their residents.