You need to hang with people who are more intelligent than your friend.
Currently, you can cheat all on your own without the collusion of anyone else.
With the FairTax, two or more people must be involved in order to cheat the system. Both run the risk of the other being 'the cop'. You won't even be able to trust him because he may be offering to find cheats to reduce his sentence after he gets caught doing the same.
Would you really risk jail to save a few hundred dollars or even a few thousand?
I have not identified anyone lately that would even come close to qualifying.