To publicly berate and humiliate an individual. It is implied that the subject has earned contempt by some by their actions. It is a reference to Bill Oreilly's interview with Barney Frank where Frank was called a coward for telling the American public that Fannie Mae and Freddie Mac were sound and worthy of investments 2 months before they went bankrupt, and not performing his responsibility of monitoring their financial condition.
If you don't stop lying, your going to get barnied by me.