As far as I can tell from reading first hand accounts, Rebs were not allowed, by standing order, to take arms into any towns in PA the camped near. Unarmed men usually do not "pillage".
One irate farmer stamped into the tent of one of Hood's regimental commanders demanding that he discipline the men that had shot and taken one of his largest hogs. ``I heard a shot, followed by a loud squeal,'' related the farmer, ``and when I went out on the porch to investigate I noticed two soldiers carrying the hog away and they were headed for this area.'' When the colonel asked the man if he was sure that he heard a shot and then a squeal, the farmer responded affirmatively. The colonel then informed the farmer that he must be in the wrong camp, ``for when a Texan shoots a hog he don't squeal.''
http://4thtexascob.com/History.html