NSA whistleblower Edward Snowden warned that the use of surveillance to track coronavirus cases during the pandemic could continue once the crisis subsides, according to a report.

“When we see emergency measures passed, particularly today, they tend to be sticky,” Snowden said in an interview with the Copenhagen International Documentary Film Festival, CNET reported. “The emergency tends to be expanded. Then the authorities become comfortable with some new power. They start to like it.”

Snowden, who released highly classified information from the National Security Agency, said governments could extend the access they have to monitor people’s personal information during a crisis.

During the coronavirus outbreak, governments could raise concerns about public health and send orders to smartphones and fitness trackers for information about pulse and heart rate.

Once the pandemic ends, they could raise other fears, like terrorism, and continue to gather the data.

“They already know what you’re looking at on the internet,” Snowden said. “They already know where your phone is moving. Now they know what your heart rate is, what your pulse is. What happens when they start to intermix these and apply artificial intelligence to it?”

The report said the US government is working with Facebook and Google to use location data to keep track of where coronavirus cases are concentrated.

Snowden fled to Russia after the Justice Department unsealed espionage charges against him in 2013.