Researching online led for me to find this article that may help.
It was said:
If you carry a cellphone, police can track your whereabouts simply by requesting the data from Verizon, AT&T and other service providers.
In Carpenter v. United States, the justices will ponder whether this warrantless seizure of cellphone location records violates the Fourth Amendment.
So, in explanation, this means if anyone wants to track you, or let's say they think you are apart of a crime, they can easily locate you.
This can bring fear to people.
They may not feel safe. Or that someone is stalking them to kill, or hurt them.