There is socialization that brings the guardian into thr real world, teaching him & exposing him to as much as possible yet does NOT require the dog to be pet by the world.  I've been doing this successfully for years.  I have dogs in & out of schools, training in public parks.  I`ve had a 3 yr old come fling her little arms around my dog`s neck 3 minutes after he brought down a mugger.  No harm to the child.  But the Dad had to let me bring his daughter to him.  I let small children pet my dogs.  The adults cannot.  My dog doesn`t need the affection from strangers to be socialized.  We go to public places, have had strangers who don`t listen touch.  This doesn`t provoke attack but will get the person warned generally with a scary look.  Stabilization exercises make the difference. Dogs need to see that raised voices aren`t causefor attack.  Theguardian needs a full education on the odd ways of humans but a threat is to be neautralized.  But socialization doesn`t mean he has to be handled by the masses.  I would never allow a guardian to be fed by anyone...ever.  I have 2emergency people taught to handle my dogs in case we were in a car wreck or something beyond that you have to reside in my home to feed my dogs.  Criminals &sickos posion dogs or feed them to get past them.  I know because I`ve been called in to fix the problems or train their new dogs.