How to Play against the Italian Game as Black with 4. 0-0

How to Play against the Italian Game as Black with 4. 0-0

What should you do as Black if White castles on move 4 in the Italian Game, leaving the e5 pawn up for grabs? Should you break chess principles by pawn grabbing in the opening and moving the same piece twice? I say yes (and so do Stockfish 7 and a whole bunch of chess masters)!