The Facebook wall is our social document of record. Etched in rock like an Attic tablet, the things said on a wall provide a poignant look back at who said what, and when. Not anymore. Timeline lets you rewrite history.
I noticed today while trying to delete some banal crap off my wall that I was able to, via the new "Edit or Remove" pencil icon, change the date of someone else's wall posting. So I did. I literally moved what she said back in time, to a month ago (albeit with a tiny clock icon indicating as much). Then I pushed further -- I moved another friend's wall post back to 2006, years before I would even meet her. Luckily, the space-time continuum seems to have maintained its integrity, but what the hell?
What a dishonest, bizarre feature! It must either be a bug or terrible design, because I can't imagine any reason why it'd be in Facebook's interests as a social network to allow us to completely revise our social history. Timeline is about life events, such as "overcoming illnesses" and "new relationships", which have to be added manually -- so the ability to edit those make sense. But being able to fling correspondance through past and future? What sort of science fiction Timeline is this?