Most of you have probably noticed this already, but demons do not stop at the town gates in Diablo III. Certainly not outside of Tristram, and I used to enjoy retreating from that first pack of scavengers and leading them back over the bridge and into town, during the Beta test.
That was just fun and games with some weak low level enemies, though. It gets real on the higher difficulties, and if you run into a nasty mob of grotesques in the Weeping Hollow on Inferno, don’t expect running back into town to save you, as this video shows. It also demonstrates the truism that anything is funny when sped up and played to the Benny Hill music.