The past addresses thing is kind of spooky. I once got a bequest of stock options from the company I worked for and they were claimable online. One of the ways in which they verified my identity was to have me pick out actual addresses I’d lived at in the past (one of them more than 15 years prior) from a list containing other addresses. Somebody with access to a list of my past addresses might have been able to claim my fifty grand worth of options before I did.