See, but that would be crazy. If what they're saying is true (and there's no reason to doubt it at this point), they're using this in order to provide you with a service: the ability for your phone to know where you are in your city. Calling it "tracking data" is wrong, even.
Given their description of how the cell tower/hotspot data is used, it seems like deleting "this cache entirely when Location Services is turned off" is the opt-out you are looking for.
I wish people would stop saying this. Of course it's tracking data. There's nothing wrong with that. One of the phone's features is tracking your location so you don't get lost.
Personally I think Apple has overreacted. They just need to provide a configuration setting for the size of the cache, and more importantly not include it in backups. A cache is not important enough to back up. But as far as the size of the cache, the defaults sound sane enough.
You could also call the IP address that you're sending email from 'tracking data' if you wanted.
Hell, I get a text message from Rogers the second I land in the US to let me know that roaming rates apply. The fact that I have a device that has to talk to another end point means that I can be tracked.
Yes, I would call that tracking data. But unlike IP address headers, this cache contains information that is by design displayed to the user to help track their location.
I'll admit to typing "tracking data" after misreading the following bit of the release:
Apple is now collecting anonymous traffic data to build a crowd-sourced traffic database with the goal of providing iPhone users an improved traffic service in the next couple of years.
"Tracking" vs "traffic". [shrug]
But I'd still strongly prefer to be able to opt out. GPS still works to find location without this data, it's just slower. I should be allowed to take that hit, for the trade-off of not sending in data. As biafra says below:
Tracking data is only anonymous if it cannot be de-anonymized. Since I cannot check that this is not the case (with Apple, Google and Skyhook) I have doubts about the so called anonymity.
Hm, although an opt-out option might seem a reasonable request, Apple has to draw a line somewhere. If you want to have fast and accurate positioning, you have to provide them with your anonymous tracking data. That's the tradeoff, which I think is also reasonable to most people.
(I wish Apple would take that same stance with regard to crash logs. If you want stuff from the App Store, you have to let iTunes send your crash logs to the developers, without having to ask for permission first. There really is no good reason why anyone would need to opt-out of that.)
"If you want to have fast and accurate positioning, you have to provide them with your anonymous tracking data."
No I don't have to.
I am currently working on an offline positioning system based on a (hopefully complete) dataset of all GSM-Cells in the world (http://myapp.fr/cellsIdData/). The sqlite3-database is currently 25MB big with some room for optimization. I do this for Android but the iPhone also has enough space to hold this data. Although I think it would be impossible with iOS because of missing APIs to be notified when the cell tower changes.
I'm sure that cell towers are enough for Assisted GPS to get a quick fix.
If people would have found a data set of all cell towers ids and coordinates no one would have had concerns about privacy.
Tracking data is only anonymous if it cannot be de-anonymized. Since I cannot check that this is not the case (with Apple, Google and Skyhook) I have doubts about the so called anonymity.
edit:
I am looking for a comprehensive dataset of wifi access points MAC-adresses and coordinates
I should've been clearer: I didn't mean "have to" in the sense of "strictly technically necessary" but more along the lines of "if you want to use this functionality, you'll have to help us out by collecting the data that'll make it work better for everyone".
Whether or not the collected data really makes the positioning that much better, I don't know, but Apple apparently seems to think it does.
From the transcript of the phone interview Steve et al did with All Things D:
"Jobs: If people don’t want to participate in things, they will be able to turn location services off. Once we get a bug that we found fixed, their phone will not be collecting or contributing any crowdsourced information. But nor will it be calculating location."
So it looks like you will be able to opt out completely, if you really want that (but then what's the point of even having an iPhone?).
- reduces the size of the crowd-sourced Wi-Fi hotspot and cell tower database cached on the iPhone,
- ceases backing up this cache, and
- deletes this cache entirely when Location Services is turned off.
Looks reasonable to me. The only thing missing that I'd like to see is an option to opt out of the tracking data (anonymous or not).