Death, taxes, beating Arsenal, FA charging Diego Costa with misconduct. Life's certainties. The Sun also rises.
It is alleged his behaviour, after being shown a second yellow card in the game, amounted to improper conduct.
He has until 6pm on Thursday 17 March 2016 to respond to the charge.
Meanwhile, the Chelsea striker has until Wednesday [16 March 2016] to provide his observations to The FA in relation to an alleged gesture he made towards Everton supporters while leaving the pitch at half-time.
-source: The FA
The first charge is regarding Costa's behavior after the little nuzzle with Gareth Barry. While I don't recall anything out of the ordinary happening afterwards, apparently The FA have found something objectionable.
The second charge, which, for whatever reason, has a different deadline for response, is regarding some offensive gestures Costa may have made towards the crowd (who were no doubt sitting on their hands and behaving as model citizens). Again, this is something that I haven't seen, but apparently others have.
So there we have it. Just another episode of Law & Order: Costa Crimes.