A saying that many Brits have been saying after BBC's Sherlock's (2nd) Season Finale had aired. They started saying these things because on the episode, Sherlock died in disgrace, everybody believing that he had made Moriary & other cases up in order to gain more public popularity.
A sign to others that you are a Sherlockian.
(In other cases, "Moriarty Is Real" suffices as well.)
All of a sudden, a Sherlockian fangirl appears and shows the non-believing ninnymuggins the badge on her shirt. 'I.B.I.S.H.' was written on it in beautiful magic markers.
"MORIARTY IS REEEEAL!!!" Says the fangirl, and she throws a BAFTA at the non-believing ninnymuggins in anger. "Fuck you, Martin Freeman won a BAFTA!" She screams, then walks away proudly.