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.