Then you should definitely invest in KCG and see what happens.
I don't really think it'd make sense to invest in Knight or any company like it until trading volume improves across the board.
Why defend this group of criminals?
As I imagine you know, I enjoy exposing scams. But before I call them scams I make very sure that's what they are. And I don't label anyone a "criminal" until he or she is a convicted felon.
So why are you flinging around these terms without any kind of proof?