These groups, although still VERY Dangerous and still very much active, are beginning to feel how irrelevant they've become to the world as a whole. They'll claim ANYTHING to keep themselves in the conversation.
"MAN SLIPS ON BANANA PEEL, HURTS HEAD AND BACK: ISIS CLAIMS RESPONSIBILITY FOR BANANA PEELS PLACEMENT!"
"MAFIA DON SHOT BY RIVAL FAMILY; ISIS CLAIMS TO HAVE RADICALIZED THE MAFIA!"
and so forth. Bunch of douchenozzles.