Not that anything organic actually happens on Facebook but to the degree it does, it must surely be in how profiles of the deceased are used by their friends. As is our custom as humans who have been visiting grave sites for millenia, leaving flowers, notes and memorabilia.
Same goes on Facebook. Their profiles have become a diary of remembrance. Sweet. Funny. Heartbreaking. And a place to linger, perhaps a little too long. A simple click can take you on a journey that takes you back decades.
Facebook itself provides a way to report a dead friend and have their profiles memorialized officially - as if official is any more real on Facebook than organic.
One more thing. Happy birthday, Cindy. Miss you.