Two things... hacking and modifying, which would alter the control systems that the programme has been developed (at great expense in research, design, and implementation) to operate. Some of these programmes integrate the GPS/DGPS with an 'auto-pilot' function. We're not talking about replacing a fuel filter or fixing a flat tyre, this is about the big tractors and self-propelled (combines, industrial-level seeders, etc...) implements whose programming would be stolen and applied to other makes of tractors/implements.
Secondly, have you noticed that ALL of these news articles (5-6 different threads here on TBN alone) target/refer-to/mention ONLY John Deere. What does CASE IH have to say about the subject? Oh wait... their head office is in Italy. Any other big tractor manufacturers happen to actually be from the US?
<sounds of crickets> <<a tumbleweed rolls by>>
Yet no one has asked the 'foreign manufacturers' to release their programming.