Rogue pools

[Undercover]

I am looking for holes in the system.  Not because I want to exploit them. It because I want to trust the system.

What if a large pool of miners goes rogue.  The Evil Mining Pool (EMP) decides to only recognize and work on blocks that were created by other miners of the EMP.  They could have a hidden handshake, the address for the new coins in the block could have a particular hash only recognized by EMP miners.  Also when an EMP miner discovers a block ( or nonce, or POW, whatever it is called) they don't broadcast it to the world immediately.  The EMP starts working on the next block without telling anyone outside the EMP what the block is.  They could be two or three blocks ahead.  As soon as someone outside the EMP releases a block, the EMP releases there's, and maybe one ore if they are 2 or 3 ahead.

Is this discussed anywhere?