Also Dierdre Skye look at the Kasparov Deep Blue game I posted.Kasparov was a lifelong Sicilian player. He knew more about the Sicilian than anyone who's ever lived, and he immediately reached a position straight out of the opening that is just completely lost for black by move 17. This was in the 1996 match when Kasparov was still much stronger than Deep Blue by the way, but he still got destroyed by the Alapin against an opponent much weaker than himself.
c4 is more explosive than c3.
c4 accomplishes nothing though