https://wccftech.com/carpenter-vs-united-states-warrants-required-to-collect-cellphone-data/

In a landmark ruling, Supreme Court has decided that the government will need a warrant if it wants to collect location or other phone data. The 5-4 decision has an impact on all kinds of personal information that is held by third parties, including location, browsing history, financial records, email, and text messages.

The court suggests that the Fourth Amendment guarantees an expectation of privacy. By allowing police to be able to track a person second by second is a kind of surveillance that should not occur without a search warrant.