I'd guess....morbid autograph collection.
Look at those people who got a hold of John's address. ....
Maybe signatures on a death certificate print out. ....then hours later. .UP ON EBAY!
***ALL BAD HUMOR ASIDE :
What's the reason for the question? Could be a potentially interesting thread.
What is the equivalent of HIPAA law privacy and retention overseas in the UK?
If you were looking for research that is....