According to a report from the Wall Street Journal, the government is using data from the mobile advertising industry. Government officials at the federal and state level, as well as those at the CDC,  having been tracking the movement of the public to better understand the COVID-19. 

Data collection doesn’t include personal information, such as name or number. This still raises privacy concerns nonetheless. The government says they is all to make sure citizens are complying with the stay at home and shelter-in-place order. These circumstances reduce our privacy to less than what it is. We are uncertain of how the government will use this data after the threat of COVID-19 drops.

Taking a different view the data could come in hand can see this data as invaluable to tracking the spread of the virus. The issue is people have to volunteer the rights to their location at all times.

https://www.digitaltrends.com/mobile/government-tracking-mobile-data-coronavirus/