The way this is headed sounds like: "if you don't want to be tracked, leave the cell phone at home". However, it's unclear as to when the tracking info was received. Was it while looking for a suspect (fishing expedition) or after they had a suspect and were adding to the evidence pile? If I'm standing outside a bank at 9 am every morning, and at 9:05 one fine day it's robbed, I guess I'm a suspect. Or a guy waiting for a bus. Phone data says I was there, witnesses say I never went into the bank but got on the bus.
I think that "probable cause" and a warrant for phone records needs to be established and if it takes Congress to pass an act to clarify the Constitution, then so be it.