So you suggest we should allow law enforcement to track cellphones without a warrant because its obvious the guy was a criminal?
They didn't track him. They didn't track anybody. What about what I said makes you think I'd be okay with cops just tracking cell phones?
I don't think you understand what happened in this case, and what a court order is. The cops didn't actually do anything, or track anyone. They got a court order for the phone company to hand over specific, limited billing data for one guy for whom reasonable cause had been demonstrated to a federal judge. That's how the whole system is supposed to work.
They can't just barge in to the phone company and seize their records. Is that what you think is going to happen? A judge always has to review it. That's a requirement of the SCA (the Stored Communications Act). And if the judge does a shitty job, the defense attorney challenges the validity of the order. Oh, and the SCA precludes phone companies from voluntarily handing over this call data. An order MUST be obtained from an impartial magistrate.
This is a higher standard than other business records already. Your bank records can be subpoenaed by a clerk of the court (and challenged by the bank if the bank things they aren't relevant to anything the court is doing). That requires no judge.
And a warrant would be worse, because warrants authorize the cops to do the searching, rather than the trust the holder of the evidence to hand it over. So instead of a court order compelling the phone company to hand over specific documents (meaning they can take care to limit disclosure to only the things the court needs) you've got the cops coming in to the phone company and rummaging through everybody's stuff until they find what they want. Again, with a judge's approval.
The meat of this case is that the defense argued that the cell location data constitutes a search of the defendant, rather than an order to produce to the phone company (for their records...remember, "your phone records" are not your phone records. They're the records of the operation of the phone business). But the judge said "no, that's bull because you're using a cell phone, which everybody knows has to connect to a cell tower, of which there's surely a record."
The 4th amendment protects you from unreasonable search and seizure. Not all search and seizure. If that were the case, there would be no warrants. What about this particular order to procure records do you find unreasonable?