If the IRS decides to pursue FCF and The Family, based on legal declarations that indicate tax fraud, they will find out what being mauled by a pit bull feels like.
Many big time criminals are doing upwards of several lifetimes in prison for tax evasion. All the cute slip and slide moves they do won't help as the family bosses find themselves hooked up to a pain amplification unit inside a hurt locker.
IMO one of the big 'crimes' against the USA is considered to be tax fraud. Uncle Sam will not tolerate losing revenue through tax evasion. Greedy people who are stupid enough not to 'tithe' to the tax people generally get little mercy, particularly in the wake of the large number of huge fraud cases over the last few years. They may become just another shell company charity fraud corpse mangled by the IRS and dangled somewhere in Hell's half acre.
I expect that the fam will try to run as the faceless blue suit raptors of the IRS begin to work their way through the family's economic food chain. In the real world the men in black are the IRS. They don't need permission to freeze assets like cars houses and the clothes off a felon's back. They can sneak up on you and wisk you away at anytime.
All I can say is they better be good at running or living like nocturnal apes in a cave somwhere. American express, offshore accounts and false documents will not help them. People who turn in or catch tax cheats may be eligible for a reward or bounty. In the jungle on the run they also may be robbed or eaten by a host of bugs, snakes and other such creepy things that don't care how important you may have been in the imaginary flea profit kingdom of dung to dust berg.
Pardon me, I don't mean to gloat, I just had to vent!