Wasn’t there a federal law passed just a few years ago that you cannot use GPS or triangulation to find someone unless there is a warrant out for their arrest? Police can’t find missing persons that way anymore, I think.
Law enforcement uses “parallel construction”.
They collect the phone information (sometimes legally, often not) to get the bread crumbs to help them put together the case.
Then they collect evidence that can be used in court that matches up with the bread crumbs.
The law becomes irrelevant with such an approach.
Thank GOD! a law was passed!
I think the FBI Crossfire Hurricane gang just put that one to rest by altering/forging documents to trick a judge into giving them a FISA warrant on Carter Page.