The lesson bad guys (other than cops) get is, "Damn! This is too easy. All I have to do is kick a door in and scream 'Police! Search warrant!' and even the most innocent and well-armed home owner is going to drop his weapon, hit the floor, and involuntarily wet himself. Thanks for conditioning my victims for me, Mr. Trigger Happy Policeman."
Perfectly rendered.
No-knock entries are *UNCONSTITUTIONAL*!!!!
If you think there’s a danger, you need to find another way to get the perp.
But entries *MUST ALWAYS* be preceeded by a knock and the presentation of a warrant.