Efforts to pass a bill that would allow the IRS to deny travel rights to U.S. citizens who the feds merely claim owe $50,000 or more in delinquent taxes represents a de facto move to revoke the citizenship of Americans without due process and in complete violation of the Constitution.

Forget $50,000 dollars, people like Warren Buffett owe nearly one billion dollars in back taxes going back a decade, but I doubt you’ll see Buffett being apprehended by the TSA on his next business trip if this bill passes Congress.
http://www.newsmax.com/InsideCover/buffett-irs-back-taxes/2011/09/01/id/409520