Having been hit over the head with 1 1/2" pvc tube (don't ask), I can tell you it's just as good a bludgeon as aluminum. Someone should put together a TSA Greatest Hits article; one of my favorites was not allowing flyreels in carry-on because the line could be used to strangle someone. TSA is an endless source of amusement, unless your on the receiving end of one of their 'episodes' in which case it's an endless source of frustration, anger and anxiety.
Regards,
Scott