Step one: Procure whatever hardware necessary to force difficulty to continue increasing.
Step two: Wait until the power requirements for running a mining setup from a single family dwelling becomes next to impossible.
Step three: Mop up any remaining centralized mining facilities through either taking them over in the name of national security or bombing it into the stone age.
Step four: Profit.

I wouldn't doubt that the NSA already has this kind of scheme cooked up and ready to deploy.