Where you gonna get a hubcap these days ??
I gotta couple of spare mag wheels you can buy instead, stop anything !! (except the rain coming through between the spokes)
I think people love this kind of stories, especially considering 99% of the populace doesn't look up or isn't really interested in anything else but what's happening at ground level or on facebook. So anything goes really. You could create mass hysteria overnight just saying that a massive rock is going to fall on our head tomorrow. TBH in retrospect before getting interested in astronomy and learning a bit more I might have believed some of the stories you get in the media at times.
This sort of stuff was going around even before internet. The net just makes it easier. I remember back in the 1970's loonies were traveling around giving lectures, writing books and making cassette tapes about things like "the Jupiter effect" of the great planetary lineup of 1982 and how we were all going to die from the massive gravitational force exerted on the Earth.
Don't show this to the gov't or they will find a way to save us all and Tax us to pay for them saving us 
at the same time GAWD!!! 
I guess i'm going to die from the debris of ISON 
