"To avoid the draconian locks that John Deere puts on the tractors they buy, farmers throughout America's heartland have started hacking their equipment with firmware that's cracked in Eastern Europe"

MB:

Tractor hacking is growing increasingly popular because John Deere and other manufacturers have made it impossible to perform "unauthorized" repair on farm equipment

...

a fear I heard expressed over and over again in talking with farmers, is that John Deere could remotely shut down a tractor and there wouldn't be anything a farmer could do about it