Via: Jonathan Zdziarski 
Sept 21, 2011
I canceled the OnStar subscription on my new GMC vehicle today after receiving an email from the company about their new terms and conditions. While most people, I imagine, would hit the delete button when receiving something as exciting as new terms and conditions, being the nerd sort, I decided to have a personal drooling session and read it instead. I’m glad I did. OnStar’s latest T&C has some very unsettling updates to it, which include the ability to sell your personal GPS location information, speed, safety belt usage, and other information to third parties, including law enforcement. To add insult to a slap in the face, the company insists they will continue collecting and selling this personal information even after you cancel your service, unless you specifically shut down the data connection to the vehicle after canceling.
Anonymized GPS data? There’s no such thing! We’ve all seen this before – anonymized searches, for example, that were not-so-quite anonymized. But in this case, it’s impossible to anonymize GPS data! If your vehicle is consistently parked at your home, driving down your driveway, or taking a left or right turn onto your street, its pretty obvious that this is where you live! It’s like trying to say that someone’s Google Map lookup from their home is “anonymized” because it doesn’t have their name on it. It still shows where they live! What’s unique even more-so to OnStar is that the data they claim they sell as part of their business model is useless unless it’s specific; that is, not diluted to the nearest 10 mile radius, etc. This combination of analytics, and their prospective customers (law enforcement, marketers, etc) requires the data be disturbingly precise. Anyone armed with Google can easily do a phone book or public records search to find the name and address that resides at any given GPS coordinate.