MENLO PARK, Calif.—In what’s being described as one of social media’s biggest reversals of fortune ever, Facebook has gone down—and is posting status updates on Myspace, its once formidable, long obsolete, but now trending rival. Although it’s not known what’s causing this latest and most severe Facebook outage, there’s increasing speculation in AOL chatrooms that My friend, Tom, may have had something to do with it because he recently changed his profile song to Alicia Keys’ hit “Karma.”