Well, this is common sense. Remember the "Ecce homo" painting? there are some things that will likely go wrong if you do them by yourself. Sometimes with conseq

Well, this is common sense. Remember the "Ecce homo" painting? there are some things that will likely go wrong if you do them by yourself. Sometimes with consequences that are not desirable for "the common good". This includes repairing devices that are required to be reliable for public safety.