They Stormed the Capitol. Their Apps Tracked Them.

In 2019, a source came to us with a digital file containing the precise locations of more than 12 million individual smartphones for several months in 2016 and 2017. The data is supposed to be anonymous, but it isn’t. We found celebrities, Pentagon officials and average Americans.

https://www.nytimes.com/2021/02/05/opinion/capitol-attack-cellphone-data.html