OK so doing a little checking into what states allow open carry and restrictions and of course the Wiki came up but the map and explanation is helpful
http://en.wikipedia.org/wiki/Open_carry
so it appears that PA is an Anomalous open carry state which means there are some restrictions in place for various reasons.
I would think this man had researched those restrictions before pulling this stunt and if not he is a moron doing more harm than good in this case.