The are copying content wholesale to keep the traffic from getting there.
Though they are supposed to do a cache refresh every time someone hits it.
With reports of BING DOSing site scrubbing for content (and specifically using robots.txt as a guide of *where* to go), I seriously doubt they are playing by the (implied or otherwise) rules.
I'm reconciled to the existence of idiots in the world, but I'm bitterly resentful of whoever it was who first thought to make computer technology available to them.
106 ms