Hm: If this is an urban legend, it appears that the basics of it have been knocking about for some years, if not centuries. Zombies, anyone :-) ?

The version I heard (once), at the peak of the spiked-drinks scare, was of someone waking up The Next Morning to find all his savings signed away, and the signatures were all his own. And that, mesdames et messieurs, is where the third verse of my version of Black Velvet Band came from.