As can be seen in the real world, the technology is trusted. Part of why it is trusted is that it provides repeated and dependable behavior. Even if the technology had a way of recognizing who is a "good" person that list either has to be populated by the owner or determined in some other way. The core question is, does technology as it stand have the capacity to judge correctly every time? This is something that designers have to take into account when developing a system because either the system has to be sure or the response has to be moderated. If not, a single misjudgment becomes societal distrust of a whole set of technologies, just like when a dog attacks a child the whole breed comes under suspicion.