The problem is that there is a big confusion about building the technology and using it in some specific, wrong way. Surely anyone here will agree that building the technology itself should not be forbidden. You can do it for some valid reason, or simply for fun. It’s not for anyone to judge or stop you from doing it. Those who use it for some nefarious reason must then answer for that. Guns are the obvious comparison (although maybe not the best) as in they are needed for protection also. But another example is how explosive devices and technologies can be used in a variety of useful ways, such as mining, terraforming, etc. Using someone’s image without their consent is already a crime and applicable in many other non-DF scenarios.