Or maybe it's a bike theft prevention system (while wearing parka, snap belt around bike frame, and carry bike behind you). (See, e.g., http://www.bikeforums.net/showpost.p...83&postcount=1)

Or a handy moose cage (just in case for those longer rides in the woods). (http://www.bikeforums.net/showthread...ighlight=moose)