US Customs and Border Protection disclosed a data breach of photos of travelers and license plates .
The breach was discovered last month and involves fewer than 100,000 people who passed through one land border crossing, an agency spokesman said.
A CBP contractor was hacked, which the agency refused to name but is thought to be Tennessee-based company Perceptics.
"Initial information indicates that the subcontractor violated mandatory security and privacy protocols outlined in their contract," CBP said in a statement.
"No passport or other travel document photographs were compromised."
Perceptics says it is the only provider of license-plate scanners at all US-Canada land border ports and at many on the Mexico border.
The breach was restricted to images taken of travelers in vehicles entering and exiting a single land border point and does not include any other personal data.
"None of the image data has been identified on the Dark Web or internet," the CBP said.
It didn’t impact any travelers passing though airport border points.
It has sparked more calls for the government to scale back plans to expand collection of sensitive traveler data.
"This incident further underscores the need to put the brakes on these efforts and for Congress to investigate the agency’s data practices," ACLU senior legislative counsel, Neema Singh Guliani, said in a statement.
"The best way to avoid breaches of sensitive personal data is not to collect and retain such data in the first place."
