He has learned that his behavior is ok and it sounds like play. Does he do this in the house or outside? Keep him on leash when people come into the house. Make him sit until the people have entered and they are seated. Tell them no talk, no touch, no look. Teach him "calm" for when he encounters people. When the dog is calm, allow him to sniff the people but tell them to not touch, talk or look at him. Once he sniffs them and he remains calm, allow him to free roam. If he becomes excited, bring him back to sit. Either place him in his crate or teach him whatever word, i.e. "place", meaning he must go to a specified location and lay down until he calms down.
What does his body language tell you when he does this? Is he playing or does he mean business? Learn your dog's body language. Does he fixate on the person when he sees them, meaning he stops and zeros in on them and sees nothing else? Does his head get lower and his body stiffen? Does he lick his lips or yawn? What is his tail doing?
He is now in the "teenage stage" and this means you back to basic training with him. Adopt NILF (nothing in life is free), he must work for his food, treats and affection. Make him do a set of commands before giving him any of the previously mentioned things. Have him sit, paw, lay down, up, sit and look at you before he is fed any food. This stage is where he will test the limits and not listen a lot, remember when you were a teenager? This stage requires consistency in training, LOTS of patience and HUGE amount of alcohol (for you not the dog). Do not let the dog feel your frustration, as this will causes him to shut down and stop listening even more. When you become frustrating, stop and walk away from the training or situation. Take some deep breaths, return with shoulders back and stand tall. This lets the dog know that you've got it.
