A court just said that geofence warrants, which let police look at where people's phones have been, are illegal.
These warrants are used to figure out who was near a crime, but the court said they violate our right to privacy.
They allow police to look at way too much information from lots of people, even if they haven't done anything wrong.
This ruling is important because it helps protect our privacy and says that the government can't track our every move just because they think we might be guilty of something.
