Aerial conduit isn't strange, you havent noticed it because it's usually black. It is usually for fiber though. It's almost the same product as the orange subduct used in burial for the same application.
I've seen lead cable and lead cable hanging from staples/rings instead of being lashed, but never lead conduit, at least not aerial. I was at a customer house once that had a lead conduit sealed in the wall the drop came out if, but that might have just been the jacket of the ancient drop.
