EDITED: Sorry for the overlap...I didn't see your post when I posted!
Personally, I would let people toss him treats if this were my dog.
I agree with Sandy (hi Sandy!!
) I would certainly do this if this were my dog. And it doesn't have to be treats...does he like a ball? You could have them toss a ball to them. Treats are easier, but some dogs (like mine) are just more motivated by balls. Otherwise, hotdogs cut into nickel size pieces, small pieces of bacon or cheese works well, too.
My concern is that the dog you're describing sounds like he has the potential to become a fear-biter as he matures if he isn't somewhat desensitized to people (at one year old, he really is still a pup). I'm not saying he *will*, I'm just saying you are describing the habits of almost every fear-biter I've ever met, so it's best to take some sort of action now---which it sounds like you're doing.
How's your boy with kids? The truth is kids are at the highest risk for being bitten because they're, well, kids!
You don't EVER want the dog to take that first bite or snap. If he does, and he gets the result he wants (the person backs away), you won't believe how quickly that behavior will escalate.
Keep bringing your dog into situations with people. In general, dogs will get desensitized to things they have to deal with often, as long as it's not traumatic.
My goal wouldn't be to have the dog love everyone he meets. I like aloof dogs, and it's common for GSDs to be like this with people outside of their pack...I like that about the breed. But you want him to feel comfortable, too, not scared. Being anxious all the time is no fun for the dog, either.
If it were me, I would get a vest with a patch that says "Do Not Pet". Some people will still approach you to ask "why not?" but they will generally keep their distance at first, and won't talk with their hands first. This way you can limit the number of people approaching him, and do the treat-giving at a gradual pace. You could tell these people that you're trying to build up your dog's confidence, and would they mind throwing a treat to him, but not petting him. I've found that most people are willing to help.
And don't beat yourself up about the doggy daycare. It's possible that no one did anything to your dog. It might just be that a place like that was just too much stimulation for him. A person could have just dropped a whole bunch of metal bowls by him by accident and scared the crap out of him and, viola, you have a dog that is fearful of people. Some dogs are just like that. I guess what I'm saying is...best to not worry about what happened and just get him past this. It might not be anyone's fault.
Keep your sessions short, ignore any fearful response and give him gentle praise when he acts confident. I'm sure you know this, but some people accidentally reinforce a dogs fearfulness if they say, "It's okay, don't worry" to the dog in a sing-song voice that sounds, to the dog, like praise for being fearful. And I personally wouldn't say or do anything while the dog's considering whether or not to take the treat, because remember, if he's hesitating and you're saying, "That's it, it's okay" then the dog is hearing praise for the hesitation. Only praise when he acts confidently.
We typically take him on walks (only about once a week) in the outdoor pedestrian "mall" downtown where there's lots of people around.
If I were you, I would walk him once or twice a day, not once a week, and I would do it in a place that only has *some* people, NOT lots of people. Again, gradually is better.
Think about it, if you were afraid of snakes, would it be better for you to have a pile of them thrown in your lap once a week, or would it be better to go everyday and look at one behind glass, and as you begin to feel comfortable, get closer? The pedestrian mall would be where I would take him as a final test, not the first thing.
And I would take him out every day if you can. Also, have the dog well-exercised before he goes on these jaunts. A dog with energy could very easily have that energy turn into nervous energy. A tired (not exhausted) dog will be calmer...that's the truth.
At any rate, I think your dog has plenty of potential to move past this, and I think you're very capable of being the one to help him move past it.
Good luck...and keep us posted!
Amber
Carbon