If you mortgage your house, does a vampire need to get permission from you or the bank to enter your house?
Does it matter whether or not the house is underwater or foreclosed?
What happens if your mortgage is sold off and bundled into real estate bonds, divided into tranches, and sold off to to corporations that then leverage them with collateralized debt obligations and try to hedge them with insurance default swaps?
I don't remember any successful vampire attacks from that time.