It was true for most of my life in the USA. I looked up the information again, now, and it seems in 2018 there was a supreme court decision that made it illegal

It was true for most of my life in the USA. I looked up the information again, now, and it seems in 2018 there was a supreme court decision that made it illegal for cops (but not the NSA, etc) to acquire individual location data without a warrant, https://www.npr.org/2018/06/22/605007387/supreme-court-rules-police-need-warrant-to-get-location-information-from-cell-to https://www.npr.org/2018/06/22/605007387/supreme-court-rules... . But this doesn't apply to selling to private companies who then sell their services to the government. And it also doesn't apply to the "anonymized" aggregate data of all locations of all cell users. This is still available and sold to both private and direct government purchasers. And with 2-5 years of high cadence 100m data it's very easy to see where someone lives, works, etc and de-anonymize their paths. The commercial sale of this is big business and has been covered innumberable times on HN over the years. https://news.ycombinator.com/item?id=17094213 https://news.ycombinator.com/item?id=17094213 , https://news.ycombinator.com/item?id=17081684 https://news.ycombinator.com/item?id=17081684 , https://news.ycombinator.com/item?id=17069459 https://news.ycombinator.com/item?id=17069459