Bill Hicks censored Letterman appearance

Part 1 Letterman explains how he pulled Bill's set (15 YEARS AGO!) but he's not sure why he did it:

http://www.youtube.com/watch?v=kUbB_D-dYp8

Part 2 Letterman interviews Bill Hicks' Mom Mary:

http://www.youtube.com/watch?v=5yTVDoSRKq0

Part 3 Bill's banned set:

http://www.youtube.com/watch?v=VBC1dKGO2_A