Possible Clues:

• Hate group
• Racist organisation spies drop out of ski-planes
• Hateful group
• 'The Birth of a Nation' group
• Terror group in "Mississippi Burning"
• Klux follower
• Bunch of sheetheads?
• D. W. Griffith subject
• Group seen in the film 'Legion of Terror'
• D.W. Griffith film topic