Based on that case, I'm guessing the Court would draw a pretty direct analogy to the cell phone GPS tracking - allowing it in public, but requiring a warrant for movements indoors.

Ah, but the Knotts tracking device was secretly planted by police whereas a cell phone GPS was voluntarily acquired and carried. So, in one case, you have police "entering" a home for the surveillance and in the other case you do not.

Of course, as always, you never know until SCOTUS takes and rules on a case. And it's a substantially different Court than in 1983, anyway.

However, the Court also held that once the suspect exited the car and went into a private home, the cops could not use the tracking device to monitor his location inside, because once he was no longer out in the public, he did have an expectation of privacy.

Based on that case, I'm guessing the Court would draw a pretty direct analogy to the cell phone GPS tracking - allowing it in public, but requiring a warrant for movements indoors.

I believe that what Beldar was referring to when he said "it's the entire reason he purchased it!" was that a cellular device is constantly being tracked by the carrier through cell towers, which is why it works as a mobile phone, which is precisely why the customer purchased it. It has nothing to do with voice vs. data networks; both are cellular, therefore all communication via cell phone is geographically tracked.

Not sure what you point is. I used to work for Verizon Wireless, and I have a pretty good grasp of how cellular technology works.

People buy mobile devices so they can communicate free of landlines. That is the point of why they get them. This does not mean they want third parties to track their movements simply to give carriers additional revenue streams. Carries may indeed have that buried permission to do that somewhere in the fine print, but it was not the intention of most users to give it when they got their phones.

People in this country need to start getting alarmed about the ability of technology to infringe upon their privacy. The government and corporations have show that, buy in large, they don't give a damn about the concept as it relates to citizens, only as it relates to them.

Along the same lines, James's reference to "GPS-enabled phones" being trackable is a bit misleading - since all phones are trackable and are tracked by the carrier, not just those with embedded GPS/AGPS capability.

My definition of Case law - the gradual rewriting of the constitution, without representation (Penumbras and emanations notwithstanding.)
(not schooled in law, obviously)

it's the entire reason he purchased it!

Not true. Most people buy phones to use voice & text, followed by web surfing. The primary reason for introducing GPS was to make 911 calls workable (something that has still not happened).

He similarly knows for a certainty that a commercial enterprise whose actions and decisions are wholly outside his control can, as a consequence of the service he'e chosen and is voluntarily paying for, locate him.

Only if the carrier allows it. Businesses certainly have no "right" to locate people via their mobile devices. The question is will consumers, who are paying a premium for cell service, willingly bend over and take it.

This is not much different from the notion many people have that their emails, sent on computers owned by their employers, using bandwidth and ISPs provided by their employers, is somehow supposed to be secret from their employers.

It could not be more different. And employer owns his network, the bandwidth, and the time one spends at work. I own my mobile device. I pay for the service & bandwith, and my time is my own. This should make me the decision maker in regards to its usage.

Someone pays good money — unforced by the government in any fashion — to buy an electronic device which is intended, quite literally, to determine and then to broadcast his position. He knows for a certainty that there are satellites that can track the location of that device — it's the entire reason he purchased it! He similarly knows for a certainty that a commercial enterprise whose actions and decisions are wholly outside his control can, as a consequence of the service he'e chosen and is voluntarily paying for, locate him. They can, if they so choose, pass that information along to others — ex-wives, bill collectors, or government agents — when and as they wish, without thereby violating any contractual or other "right" the customer may think he has.

The customer has no reasonable expectation of privacy in the use of this device — at least not insofar as he's expecting it (or anyone who can intercept its signals) to conceal his location. If he ever thought he did, it's because he hadn't thought about it very much, or else because he didn't understand the concept.

This is not much different from the notion many people have that their emails, sent on computers owned by their employers, using bandwidth and ISPs provided by their employers, is somehow supposed to be secret from their employers. Just because one has a strong intuitive sense that something "ought to be private" doesn't make it so, and it certainly doesn't expand the protections of the Constitution to elastically fit one's whims.