" http://www.infiltrated.net/amishAttacks.html "reported on 9th april
"Security experts are reporting today that Amish hackers equipped with reverse engineered VCIM's have hacked into Instar's vehicle satellite navigation systems and are extorting Instar."while some witnessess were also reported saying
"It's horrible. I was headed down Main Street and my Garmin told me to turn right. 20 minutes later not only was I was late for my interview, I went from being in Colorado to driving down Fifth Avenue in New York City." stated a visibly shaken John McSmith.
The article which reports the incident also shows pictures of the INstar device showing altered text. Although the authenticity of such news is a question in in itself but IMHO it seems practical to a point that the hacked VCIM can change the behavior of that particular device but not the satellite transmission itself. I would be looking forward for the details if any are released from some reliable source.