https://wccftech.com/fbi-cannot-look-at-your-phone-lock-screen-without-a-warrant/

As per a court ruling in the United States, law enforcement agencies require a warrant to even look at the phone lock screen.

This is due to the Fourth Amendment of the US Constitution, which gives people the right to be secure in "their persons, houses, papers, and effects" and prohibits unreasonable searches without warrants issued by a judge or magistrate, backed by probable cause.