freaked out or just mad?

ok so i have today off and i have been running errands, grocery shopping, doing laundry and cleaning. since we moved apartments we are now on the first floor and weenie loves to sit at the sliding door when the door is open and the screen is closed. well i went into the bathroom to clean the tub and all of the sudden weenie is barking uncontrollably, i mean barking like i have never heard before, and i turned the corner to tell him to be quiet and my screen door is open and weenie is outside running full blast at this guy, who proceeds to sit on the curb in front of my apartment and stick his hand out for weenie to sniff. weenie is just going crazy, i wasn't sure if he was going to bit this guy or not. and i yell for weenie to come back and the guy says, oh no it's ok i want to play with him, but weenie comes racing back. so i slowly close the screen door and the sliding door and lock it. and before i can realize what is going on i am thinking about how i'm going to tell this guy off and yell at him for invading my privacy and etc. etc. well i recognize him and i am pretty sure he is mentally challenged. i have only seen him once before and that is what it seemed to me, so i could totally be wrong, but can you imagine if he's not. i can some what understand if he is mentally challenged because he probably doesn't know any better, but if he's not and just some creep who tried to get into my apartment but weenie scared him. oh i just can't let my mind wander. it makes me even more scared to be home alone (which i am a lot) and it makes me super glad for weenie, he saved the day today! so i am in a sticky situation because he also lives in our building and i want to tell him that's not ok, but i don't knnow if i should. anyway-other than being a little scared or mad (not sure what i am) i am fine. and weenie is still sitting there watching out for my safety. thanks buddy! so if i don't know you don't try to come into my apartment or you will suffer the weenie consequences.