Privacy advocates gained access to a powerful tool bought by U.S. law enforcement agencies that can track smartphone locations around the world. Abortion clinics, places of worship, and individual people can all be monitored without a warrant.
Privacy advocates got access to Locate X, a phone tracking tool which multiple U.S. agencies have bought access to, and showed me and other journalists exactly what it was capable of. Tracking a phone from one state to another to an abortion clinic. Multiple places of worship. A school. Following a likely juror to a residence. And all of this tracking is possible without a warrant, and instead just a few clicks of a mouse.
Better to leave your phone at home (or better, in the pocket of someone who lives in your house and takes the same daily path as you do) if you are doing something that's currently illegal. Or in any situation where you are doing something legal that the cops are likely to break up.
The juror going home thing is terrifying but I don't think the government would be after you for fulfilling your civic duty.