Well, no sense in worrying about it. Don't keep anything valuable in your car, and less to worry about.
Insurance will cover any theft or damage.
They can also break a side window without any electronic devices.
You can't protect against every scenario out there.
To protect against this device and on-star, disconnect your battery every-time you park your car.
If your FOB won't open the doors, I'm sure their gadget won't either.
Carry that spare key with you though
They can obviously break into any car without much effort. What concerns me just a little is what they might be able to do to our cars if they break into the On Star system. Shutting your car off in the middle of rush hour traffic on the Don Valley Parkway could make things more than a little tense.
Funny that they don't say what this $5 wireless device is.... Pretty scary though.
Around here it seem thieves use another wireless device that costs $5. It's called a hammer. At least when a high tech thief steels from you it doesn't cost a couple hundred for a new window.