To take advantage of it the attacker would have to coerce someone to visit attacker's site and nastyfans site at the same time (in the same browser session) and obviously have JS enabled.
It seems that I lack knowledge about this, can you explain it more clearly? How can that be? Something called
coerce? It is really difficult to force someone to do what the attacker wants, unless they have tricks to cover the user's eyes. Right?
