I knew one man who lived and died a tax protester, not unlike Hovind and I know of one living, not unlike Hovind, a long time tax protester. There are many other lifetime un-prosecuted tax protesters, some deceased and some still alive.
How much did they steal?
Given what the Bible says about respect for civil authority, are you planning to turn them in?
Perhaps it would take a constitutional amendment to lawfully convict these folks, or perhaps, were they prosecuted, the government is concerned about opening some cans of worms, so to speak, which they want kept closed.
You can always test this hypothesis by informing the duly constituted civil authorities of their crimes. Go for it.
I believe the reason Hovind got busted is because of his notoriety as a creationist, whether or not his science was well founded.
Or maybe he was a flagrant crook.
C'mon, you might as well say that Al Capone was only busted because of anti-Italian prejudice.