content: We're reaching a point here where if this sort of thing goes unimpeded, you're not going to have much choice on the market.  Not just for tractors, although for this, I could easily see it ending up as 'pick your flavor of DRM control, or get out a sickle.' Fortunately I think the farmers aren't taking it in the face, at least for now.  But the car companies have already tried using software to prevent the resale of used cars, and almost certainly will try again.