Lol, my bully was like this too at one point. He would hear some one outside or next door and bark at all hours of the night. I would get up and firmly say to him, "No bark" several times and stare him down. If i sensed another bark coming I would do the, "Eh Eh Eh" noise I make and he would stop. Eventually he figured out that waking us in the middle of the night was not copesetic, lol. Now, he only barks if some one rings the bell or knocks on the door. Otherwise he's pretty quiet.
This is rather subjective though. I know several dog owners that like their dog barking at every outside noise, it makes them feel secure. Conversly, I know others that don't want them barking at all.