when you walk by ppl try and get as far away as possible when you walk by. when he looks like he is about to snap, jerk his leash. (not too hard) if he doesn't snap, immediatly give toby praise and a treat. you can also hold a treat in front of his nose when ppl walk by so that he will ignore them and praise if he does. i am not a pro but i hope this works. good luck!