Sharon asks…How does Facebook choose who shows up on your friends online?Some people who I've never interacted with via Facebook show up on the friends online display on chat, while people who have written on my wall don't always show up there. How does Facebook decide?Editor answers:It is not f'book that decides its just, hows everyone who is online, even if you have never talked to them on chat before, as long as you have them added as a friend then it will show u when they are online