> Contrast with the geofence subpoena. "Hey maybe some small % of people carry a phone that might send its location to you, can we check if they did?" It's ludicrous.

In the case before SCOTUS, there was a witness who mentioned seeing the suspect in a particular area and that they were on their phone. So it's not a large inferential leap to say that call records would lead to evidence of who the witness saw in this particular case.

That said, Minnesota has an even broader right, so even this sort of warrant might not pass muster in states like that.