If John Deer can disable a tractor because of political reasons (or contract breach) remotely that we can ask the question, what will stop this company , and ot

If John Deer can disable a tractor because of political reasons (or contract breach) remotely that we can ask the question, what will stop this company , and others that build in similar options into tractors and cars, from doing this again when something less nefarious happened? Or what is this system is hacked and worldwide all John Deer tractors are disabled?