The location data is said to have been anonymized, meaning that they won’t know who the location is connected to specifically. Instead, this data is being used to help health officials better understand where people are still gathering in large numbers, and how well the stay-at-home orders are being followed.
Recently, a heat map was created using anonymized location data that showed that despite the seriousness of the situation, many people are still gathering in large numbers. Social gatherings at the moment are being discouraged. This is because by reducing our contact with others, it lessens the chance of us getting infected, or if you’re already infected by asymptomatic, there is a reduced chance of you spreading it.
The US would also not be the first country to rely on location data to track the spread of the virus. It has been confirmed that both the EU and Israel have already started to use location data.