Just out of curiosity do any of you that worry about On-Star have cell phones? Did a little story on the local news the other night, VERY eye-opening. You may just want to google "cell phone spying" or visit a site like this:
Especially the part where they can listen in on your private conversations even when you're not on the phone. There has already been a case where law enforcement activated a suspected drug dealers cell phone microphone and monitored his conversations in order to bust him with the goods.
There has also already been a case where they busted a kid for doing donuts and trashing a soccer field in his Dad's Denali when they got (with a warrant) the On-Star records.
I'd worry more about the cell phone thing if I had one. Seems it is quite easy to monitor someone that way.