In the UK, Apple's Siri isn't very useful as there aren't any local data providers, and its voice recognition of the Brits isn't too good either - I stopped using it shortly after I got my iPhone 4S - I found it quicker and easier just to type stuff into Google.
Anyway, apparently Siri doesn't do the voice recognition locally on the device - it just heavily compresses it and sends it to Apple - that in itself surprises me as Siri seemed to work fine over a weak GPRS connection, without a hint of latency.
But the fact so much processing happens at Apple's end, this must mean they have access to my data for this to happen - I'm not comfortable with Apple having that kind of data available to them, so I guess no more Siri for me (not that I was really using it in the first place).
Interesting tidbit: when you disable Siri on the iPhone you get the old Voice Commands prompt instead, which (unlike Siri) works fine without an Internet connection, even for simple tasks.
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