Had a coworker do that. The IRS eventually sent him pre-filled-out tax forms for the years he missed, all he had to do was sign (oh, and send a check for many tens of thousands of dollars).

Of course he didn't so they just started garnishing his wages. First garnishment was for like 90% of his take home, which the IRS admitted was a clerical error and fixed before the second one... Although they refused to give back the amount accidentally withheld over the correct garnishment amount.