Amazon.com Inc on Tuesday launched an artificial intelligence-based tracking system to enforce social distancing at its offices and warehouses to help reduce any risk of contracting the new coronavirus among its workers.

The unveiling comes as the world’s largest online retailer faces intensifying scrutiny from U.S. lawmakers and unions over whether it is doing enough to protect staff from the pandemic.

Monitors set up in the company’s warehouses will highlight workers keeping a safe distance in green circles, while workers who are closer will be highlighted in red circles, Amazon said.

The system, called Distance Assistant, uses camera footage in Amazon’s buildings to also help identify high-traffic areas.

Amazon, which will open source the technology behind the system, is not the first company to turn to AI to track compliance with social distancing.

Several firms have told Reuters that AI camera-based software will be crucial to staying open, as it will allow them to show not only workers and customers, but also insurers and regulators, that they are monitoring and enforcing safe practices.

However, privacy activists have raised concerns about increasingly detailed tracking of people and have urged businesses to limit use of AI to the pandemic.

The system is live at a handful of buildings, Amazon said on Tuesday, adding that it planned to deploy hundreds of such units over the next few weeks.