US Marine: Knock knock!
Al Qaeda fighter: Who's there?
US Marine: (Kicks down door, throws grenade, opens fire) FREEDOM, MOTHERFUCKER!!!!!!!!
Tactical Breach Knock-Knock
Explanation
Explain Bear
Listen, soft-brain. The 'freedom' here is high-velocity lead and explosives. You expected a wordplay punchline because your neurons are firing slower than a jammed M16. Kinetic solutions require no setups.