Just found this piece about why users should be scared of Apple's push-channel to the iPhone. Quote:
Why not find out which apps are getting the most use and offering the developers special licensing deals? Better yet, why not sell that information to third parties like advertisers to help them work with highly used apps to sell ad units or sponsorships while getting an additional cut? This new tunnel for data is a veritable gold mine that's not just metrics--it's attached to user IDs and billing information too.
That's somewhat interesting, but doesn't scare me. What scares me is that Apple has a backchannel AND the device has GPS built in. I'm keenly aware that the mobile phone carriers can triangulate my whereabouts with some precision, but that's the carrier. Here we're talking about a third party that happens to make the hardware and with whom I have no contractual relationship whatsoever. I'd own the device, my contract would be with AT&T.
There's significant uproar whenever any app is trying to phone home for privacy reasons. If that is worrying you even for tiny little moment, you should be worried about what Apple is doing there.