Sure - license plate scanners store that data long-term!
That's a hot button topic. I just caught a story on the wire yesterday about a US local city level parking authority using such to catch those with outstanding parking tickets. Net result in not much time was 10's of thousands of vehicle plates snapped. Someone up to
3 times in different locations.
Problem is, the data is able to be requested by the public under FOIA and would be released.
To contrast this to State Police in the same state is day and night. They collect lots of plate data, but it is purged on a standard and quick schedule and thus, not under FOIA. Whether they feed it to other departments as part of evasion, I can't say. I can say, I hope they do not and are being fully truthful.
you can use it to spy on people, but that's not it's primary purpose
A device need not have a single function to meet some strict definition. Nor does something need to be technology to facilitate this endless amassing of information for mining purposes.
Going back into the Cold War there were energy weapons used and audio bugs that took the form of artwork in offices. Clearly, those were limited use decoys, and thus, more in line with your pure definition.
When I think of these phones (and not picking on Apple here at all), there is spying on these layers as a base:
1. All call details
2. All texts -- nice and small, easy to store, by design?
3. Location data, cell towers, wifi, etc. It may leak device name (Joe's Iphone). It may leak names of wifi (123 Main St wifi)
4. Application and phone install stack info. This could be the bundle of major installed software, or the various visible things from something as 'innocent' as the browser.
5. Intentionally leaky software -- We've seen network improvement software - or so it was called and official carrier payloaded stuff in various phone lines. Then you have the malicious apps themselves. Some you opt in and aren't paying attention or knowing of their use, others are simply malicious.
We of course have the lat/lon GPS data, orientation data (is the user sleeping now), temperature and other inferred data set info (is their noise, is there light, is there temperature).
All of these issues scream for secure computing and trusted networks - alternative networks and more anonymous functionality.