TL;DR;
Young dog is so attracted to other people that it becomes unsafe. He rushes to greet them, apparently expecting reward, and we have trouble controlling him. What can we do, apart from isolating him from people?
Longer version
We got this puppy from a shelter when he was quite young, about 8 weeks old. He's now approaching 6 months. He's reportedly a German shepherd x husky, quite large and strong for the age. Normally he is compliant (again, within the bounds of his age), understands and follows basic commands.
We live in a very dog-friendly neighbourhood; there are about two dozen dogs on our block alone. Everybody here are used to dogs on the street, and many are friendly/attracted to them. The majority, especially those who own dogs, follow the usual courtesies: they ask for permission to pet the dog or give him a treat, and give him space. A few, however, are too friendly; they come right over, start hugging the puppy, dole out treats, and generally create a commotion. Our pup was subject to such behaviour from the very first days we brought him home.
Initially we didn't try to prevent this from happening, trying not to alienate the neighbours and provide extra socialisation for the dog. However, it's now becoming problematic, as the pup expects almost everyone he meets to give him treats, hug him, and dance around all happy, to the point where he's ready to dash across the street if he thinks he sees someone familiar (which is often not the case).
We've realised our mistake, and we're trying to limit the enthusiasm of the people we meet on our walks, at the cost of making a few enemies out of the former "friends" of our pup. However, the dog is still too attracted to those he already knows, as well as other, unfamiliar people.
Is there anything we can do make our puppy to ignore/be wary of people he meets on the street? The usual game of "what's this?", "look at me", "here's a treat" doesn't work when he gets too excited and wants to run towards the (potential) source of good things.
Obviously, we don't want him to be aggressive or scared of people, just a little bit apprehensive or suspicious. Also obviously, we can't ask random folks on the street to stage performances and wave sticks/throw stones at him.
What are our options?
This question seems related, but the answer is the opposite of what we're trying to achieve.
I'm sorry, I couldn't resist adding a picture, but it might partially explain people's affection for this guy when he was younger.