v. To severely criticize, especially as a member of the media.
"I know you [media] guys are going to get me. Maybe you guys won't pencil-whip me this week, but I know it's coming."
"Pencil-whip" seems to be a blend of "pencil" (the instrument with which many media types write their notes) and "horsewhip" (in its sense of a "verbal flogging").
Over a 20-yr career in the Air Force, we used this term in the military to describe how important records were falsefied. i.e. When a record was missing an important event entry, a record entry would be made to look like the event was completed on a previous date.