...law enforcement officials said the legal questions were outweighed by real-life benefits.

That's just what I was thinking last time I held up the local liquor store. Who knew I had so much in common with the police!

Worth noting: the FBI's GPS case turned on the fact that a person's vehicle is an "effect" in the sense of the people's right to be "secure in their persons, houses, papers, and effects, against unreasonable searches and seizures". The word "effect"; it's right there in the 4th Amendment.

The court did not find that people have a reasonable expectation to privacy in public spaces (an argument made by the defense in that case). If you're out and about in public, your location isn't private. This is obvious, because it's clearly lawful for the police to simply follow you around in public.

(I'm happy if the police end up universally needing [easily obtained] court orders to collect cell tower logs, but unlike most of HN, I don't see the status quo as particularly outrageous).

The benefits of having an on-your-person radiolocation beacon are somewhat muted by the possibility of having the government use that same technology to undermine your Constitutionally protected privacy.

If there is anything that history can teach us, it's that law enforcement agencies will work hard to keep us from knowing that this is going on and they will fight to keep this tool because it makes it easier for them to do their job. Ask any cop and they will tell you that they often view our "rights" as a complete hinderance to their effectiveness.

One man's "civil rights and due process" is another man's "got off on a technicality."

For what its worth, my phone was stolen last month and had Lookout Mobile Security installed. It pinpointed the location down to a few meters. Still the cops more-or-less said, "Oh, that's nice but we can't use that." They said that civilian tracking apps that use the cell network are only usable down to the tower, matter how exact it claims to be. This was in a big SF Bay Area city with a well-funded, adequate, and tech savvy police force.

Your phone tracking software is non-binding and irrelevant in court. It says so in the user agreements you click-through. That said, its nice to have the ability to wipe and lock the device remotely.

"And in Arizona, even small police departments found cell surveillance so valuable that they acquired their own tracking equipment to avoid the time and expense of having the phone companies carry out the operations for them. The police in the town of Gilbert, for one, spent $244,000 on such equipment."

Anyone fancy taking a guess at what this might be?

This is so terrible, and yet, apart from giving money to the ACLU it's not clear what I can do about it. Theoretically people are supposed to get upset and at least vote to change the policy next election: but who do you even vote for that would change policy?

And why isn't this practice challenged in court by defendants? It seems like a clear violation of the 4th Amendment, and should result in acquittal.