Just because a punishment is on the books doesn’t mean it ever happens. I only know of one case (Randy Kehler) where the government even went so far as to take away his house. He went to jail for 6 months after he refused to promise never to return to his home. I think it was offered back to him a few years later and he refused it saying that the protest was not for his personal gain. (http://scua.library.umass.edu/umarmot/kehler-randy/ )
According to NWTRCC, major punishments by the IRS (beyond simple attempts to collect by force) are rare.
I see the question has been downvoted many times. But I can’t understand why. Can someone (perhaps one of those who downvoted) please explain why?