It doesn't bother me much for a simple reason: Sutherland's wheel of reincarnation applies to cloud computing. Right now there isn't enough processing power or storage on a portable device to store everything you would want out of a thing like this, but give it time. And then it's hardware, it doesn't have to be ad supported -- the device can know all about you, but it's your device.

So that's one possible future. And the tech they're developing is pretty agnostic to whether the information it collects is stored in the cloud or just on the device, so let's try not to be too pessimistic about something cool just yet.