Micko, a couple of people I've spoken to said that this is the first thing police look for, and that they do know what/where they go; mainly since it's emissions control
not sure of the fines, and not sure if this is true as I haven't been pulled over before
At the same time, I can't really see much of a performance gain from it, since from what I can see it's all from the plenum, and whether the air goes down the pipes to the carbon canister or with a blocked pipe, shouldn't make by any means a detrimental effect on anything
just make sure you plug up the hoses if you do remove it