Time to get Harley a big brother- a rotteweiler. A good rott will take care of three pits.
Hope Harley is not too traumatized and the same for the owners. I have no patience for this crap.
Now there's some advice that appeals to me. Our 'smaller' dog is part Rottweiler. Between him and his brother, they will scare off most potential attackers.
Don, so sorry to hear what happened. I can hardly imagine how you must have felt, knowing that both Shawna and Harley were in the middle of this mess. Hope you're able to get the situation resolved with the least unpleasant solution necessary.