My brother passed a few years ago. I was able to "memorialize" his Facebook account, or whatever they call that term. Found a link on their web site, uploaded a scanned copy of the death certificate, and within a day or so the title to his page was changed to something like "Remembering Joe Blow..." People could still post on his page, but nobody could log in under his name (just in case his account got hacked or something). It was pretty easy to do.