Just got a call from a friend in Decatur who, this morning, almost had parents scammed in the exact same scheme I almost fell for. (Documented
here in October.)
The M.O. was exactly the same: Call a kid's grandparents, pretend to be the grandson, claim to be in jail, ask for money via a special money card, and give instructions of "don't call my parents, please."
Incredible.
Fortunately, the grandparents did call my friend who had read about my experience. Plot thwarted.
A quick Google
search shows this scam has exploded in the last couple of years.
Edit: I'm trying to get the phone number of the scammers.