The automated license-plate reading technology manufacturer Flock Safety on Monday announced it has put its work with federal agencies on hold.

The move comes on the heels of an audit by Illinois Secretary of State Alexi Giannoulias which found that Flock allowed U.S. Customs and Border Protection (CBP) to surveil Illinois drivers using its license plate reading systems. The practice violates Illinois state law.

Flock acknowledged in a Monday blog post that it has engaged in “limited pilots” with CBP and Homeland Security Investigations, the law enforcement division of the Department of Homeland Security. It said the partnerships were meant to bolster the federal agencies’ efforts to fight human trafficking and fentanyl distribution. 

The company also said it previously failed to create “distinct permissions and protocols in the Flock system to ensure local compliance for federal agency users.”

Flock has recently been under scrutiny. In May, 404 Media reported that local police in some states had been looking up license plate data on behalf of Immigration and Customs Enforcement (ICE). 

On Monday, 404 reported that CBP routinely queried more than 80,000 Flock cameras and was able to perform the searches on its own, without relying on local police departments’ assistance.

Flock cameras are operating in more than 4,000 cities nationwide. The surveillance technology has become increasingly controversial and residents in some cities have fought local police departments’ plans to use the company’s product.

In June, police in Austin, Texas allowed their contract with Flock to expire after an intense backlash from members of the public.

In May, Texas authorities reportedly conducted a nationwide search of more than 83,000 Flock cameras — including those located in states where abortion is legal — to search for a woman they said had self-administered an abortion.

Recorded Future News reported in July that Flock has begun mounting its cameras on school campuses nationwide, significantly broadening its presence in local communities.