This is one of those posts with a scandalous headline to draw you in, but without anything substantial to back it up. I am quite disappointed that this came from a stalwart of a tech blogger like Om Malik. I can understand this coming from an MG Siegler or an Arrington or from the joke of a blog, Gizmodo.
It hinges on the GPS location, which Apple does, quite publicly with theing like Find my iPhone. Google does that already, and so do every other GPS device on earth. I don't even need to know if you are stationary at one location every night. I can just connect the dots on your end points of your trips and figure it out.
Heck even an app like Yelp can figure my home address, based on my restaurant searches. Facebook already knows much more about us, with or without our permission; just by using the website.