My mustang, Ranger, spent the first 8 or 9 years of his life running wild in northwestern Nevada. He had very little contact with people or people's "things". Then came the round-up (or "gather") and all of that changed. Helicopters, trucks, trailers, fences and pens, and people. Scary, rude people with ropes and squeeze pens and needles and sharp knives that they use to... well, as a long term stallion, I'm sure he didn't care for that too much. All things people related were bad things.
I got Ranger 1 year after his original adoption, just the minute the cowboy that got him could unload him (you must keep a BLM mustang for one year after adopting before you get title and can sell him). The horse still hadn't gotten over his fear of "people stuff", and in fact, may have gotten worse about it. During his first year of living around people he had mastered the art of "rearing and striking" to chase people off. A VERY effective technique. He spent a lot of time being left the heck alone.
The first 6-8 months we had our new-old mustangs (my wife, Juanita and I both got our mustangs at the same time), we tried the "sack 'em out" method of desensitizing the animals. You subject the horse to close contact with whatever bothers them, in the hope that they will realize that it actually isn't hurting them. With these older mustangs, all it did was convince them that "people aren't to be trusted, they just want to torture you". Months of little to no progress left us looking for other techniques. Juanita heard an ad on the radio for a BLM adoption that had trainers in attendance to help with the training. We attended several training sessions and came away with the understanding that there are other, better ways of going about training mustangs. Clicker training was one of those ways.
Once Ranger understood treats (a story by its self), I used the clicker training "touch" command to get him to touch things that he might normally shy away from. I say touch, he touches with his nose,
Nothing in the neighborhood was safe from Ranger nose prints. Mail boxes, signs, trash cans... but most of all, car windows. "THERE IS A HORSE IN THAT CAR!!!"... "No you moron, it's your reflection. Touch." Smudge. "THERE IS A HORSE IN THIS CAR, TOO!"..."Moron. Touch." Smudge. Every car we went past ended up with smudge marks on the windows. Moron.
Ranger finally seemed to understand that if he didn't shy away, or even finch, he wouldn't have to touch the scary thing, and that made the scary stuff less scary to him. I could feel him tense up, but he would stand his ground. He got to the point where if something caught him "unawares", he would flinch, sigh, and reach out to touch it.
We ran a riding livery a few years back, and I used Ranger to lead out some of the "kids camp" rides. As long as the lead horse is calm, the horses in the line will stay calm. Ranger had 4 years of experience dealing with people and their scary stuff by then, and was getting pretty good at staying quiet.
One day, right after crossing a narrow bridge that went over a small river swollen by spring runoff, we found the trail blocked by a pickup truck with a sign on the side, "Trophy Trout". Walking toward Ranger and me was a man carrying a 4 foot pole fishnet that had 3 or 4 fish in it. These fish were HUGE! I bet there was 30 or 40 pounds of squirming fish in that net! Ranger turned to stone, and I mean not only did he not move, but he went rigid and hard as a rock. The fellow walked right up to us, completely focused on his heavy writhing load and stuck the net almost under Ranger's nose. At this point Juanita was bringing up the rear of the ride of about a dozen 8-10 year old kids. We had stopped so that most of the kids were still on the narrow bridge, which is fairly dangerous. She couldn't see what the holdup was, so hollered up to find out why we had stopped. Ranger heard her voice and looked back at her. She later told me the look on his face fairly screamed "PLEASE DON'T MAKE ME TOUCH IT!". The fish finally ended up in the water, and the truck got moved so we could go by, but that was the day I REALLY appreciated the results of the clicker training touch command.
I'm not sure the neighbors much care for the touch command, though. I suppose I owe them an apology and a bottle of Windex. Moron.