A difficult one to handle I think here.
I walk mine in a low population area but they come all over the place with me in the back of the car.
I have never encouraged them to be friendly to people in the streets and they do tend to get noisy with people coming up to them, rearing up and growling. Can be a problem but I dont want them to trust every person they meet, I dont.
I love the story of the woman who was irate at the garden centre who had woken up the sleeping dog and was cross about the dog growling at her. I think I would have surpassed the dog's growling with the stupid individual if she went near my dogs and to tap on the window is pure ignorance.
I did see a dog last night that I dont think will be stolen, it was on the end of a lead my friend, a security guard, was holding, it is a German Shepherd with a decidedly protective attitude to its dad. He was enormous, in fact both of them are, the dog is 33 inches at the shoulder which puts his head at about 4 feet from the ground standing. I have not seen a shepherd that big before.
One of the first things I did on moving in was to secure the garden. It is possible to get in but only by climbing over 6 feet gates and walls. My neighbour was doing some work on the shared outbuilding roof. He hadn't told me he was going up there but the dogs pegged him for an intruder and all hell broke loose. I know its all noise but the volume and quantity when they get aroused is spectacular.
I do not let them off the lead if there are people on the fields. I dont want them to make a mistake with anyone.
When they are left in the car it is locked and they are protective of itif people go close, not noisy but aware.
I cannot conceive of them being stolen but I do not think I would take kindly to an attempt to do it.
