Strangely I never thought about it before because I was too much distracted by the other stuff that happened in the chapters where CP9 revealed themselves to Iceburg but right now after watching episode 243 I started to ask myself what the hell the purpose of the fake blueprints of Pluton was.
I mean think about it, the plans are there to make everyone who is interested in them think that he got what he came for. Iceburg even told Paulie to leave the fake´s behind and escape because they werent the real deal. And what do those two morons do in the end? Paulie tells the invaders that the blueprints are fake and laughs at him. What a moron. Actually they should be laughing at him for being so nice and telling them while they are still inside the building instead letting them find out at Enies Lobby.
And Iceburg isn´t any better. He is the guy who had all the forethought and made the scheme with the fake blueprints up and what does he do, he tells Robin that her group was tricked because this isn´t the real plans. WTF? What purpose do they serve then, if they actually already tell CP9 that this isn´t what they were coming for? It just doesn´t make sense to me at all.