Flock Safety, the police tech company that tracks Americans’ vehicle movements through a line of cameras, announced Thursday that it would implement several new safeguards to its products.

The changes that Flock outlined include shrinking the period for how long it holds people’s movement data by default, going from one month to one week, the company said in a press release. In cases where an officer wants to hold data longer, they will be prompted to enter a case number.

To address potential police abuse of Flock’s data on people, the company also plans to fully deploy a system it began testing earlier this year, called Audit Assistance, that will lock out a user whose searches display “abnormal activity,” the release said.

The changes are meant to help address privacy concerns and to stem officer abuse of the cameras, a spokesperson told NBC News, which have prompted some cities to cancel their Flock contracts amid a national wave of vandalism against them. But the American Civil Liberties Union, a longstanding Flock critic, downplayed the new changes as minor.

“My biggest concern was and will continue to be that they are a mass surveillance company that collects billions and billions of license plate scans every month on people who have done nothing wrong,” said Chad Marlow, senior policy counsel at the ACLU.

Flock makes a range of high-tech surveillance products, but is best known for its nationwide fleet of Automatic License Plate Readers, pole-mounted cameras that log cars as they pass popular roads and intersections, creating a massive database of each car’s movement, license placement number, make and model and time of travel.

While the system has been championed by many police forces, privacy concerns have grown. Law enforcement offices that contract with Flock do not need a warrant to access travel information and can opt to share their data with local law enforcement offices, statewide, or nationwide, creating a database of Americans’ real-time movements accessible to a range of police officers that spans much of the country.

Flock and law enforcement officers who rely on the technology say that it can be an invaluable tool for tracking suspects, and can save policing hours. But privacy advocates say that the cameras sweep up unwitting Americans into a giant dragnet, and police officers have been repeatedly accused of stalking people with the technology.

Marlow said that while he welcomed Flock shortening its default data retention time (a week is still short of the ACLU’s recommended 48 hours),the company’s proposed reforms did little to address his concerns with license plate tracking.

“Flock collects location data on virtually every car in America every month and then facilitates the nationwide sharing of that data where it can be used to target members of vulnerable and disfavored communities and to undermine the privacy and chill the behavior of everyone in America,” Marlow said.