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by mercurio 5534 days ago
I'm not the author. But I believe the O'Reilly researchers claim that the co-ordinates logged are of the device itself. It is not clear at all that this is true and the author of this post presents some evidence that would suggest otherwise.
2 comments

Sure, the article is a reasonable refutation to that part of the O'Reilly claim, and that is an important fact to clarify.

The article goes further though, and claims it's "not 'recording your moves'" and is just a "general place at a general time". I don't you can say that point-blank. As stated, I think that it's going to be entirely location-dependent as to whether the database can be treated as a "record of your moves" or not.

The author says he was using his phone and the GPS often.

If they wanted to track your moves and you have turned on the GPS, why doesn't it just, y'know, use the GPS data? Instead Apple tries to track your moves using cell towers?

Seems like the only way this would be a record of your moves would be by coincidence.

To quote from my original comment: Apple probably didn't set out to track users ... That doesn't mean the data won't be enough to track movements in urbanised areas.

Whether this is really a scandal, I don't know. But it certainly seems surprising to me.

My understanding is hte iPhone doens't actually have a GPS receiver in it at all. It only uses a fuzzily defined "assisted GPS" which is basically based completely on 3g towers.

They don't use the GPS satellites at all.

AGPS is GPS satellites assisted by cell towers, and is in the iPhone 3G onwards. http://en.wikipedia.org/wiki/Assisted_GPS

The original iPhone had no GPS and always used cell tower triangulation. This varied a lot - I remember in Manhattan, NY it could track me almost to the street number; on the other hand I once turned it on in a moving car in rural NSW, Australia and it drew a circle approximately 500km in diameter.

The device location is not logged in this database at all.

What it does is log the locations of all cell towers that it can communicate with at a point in time. So for a given timestamp, there will be dozens of points logged. So while the data will be able to say "You were somewhere in downtown Pittsburgh at 1:59PM on Monday", it won't be able to say "You were at 517 Liberty Ave at 1:59 on Monday." Also, timestamps for existing towers are updated whenever they are mapped an additional time. So if I was downtown again on Thursday, no one would be able to tell from my data that I had been there on Monday.

See my previous comment in another thread for more detail:

http://news.ycombinator.com/item?id=2467895

Does it record signal strength from the towers, which would allow triangulation?