[evgen]

Because not stepping up when asked to perform such a task opens you to obstruction of justice charges. Is a building super somehow not compelled to open a door in a building if they have the key and the agents of the government present a valid warrant? When they have a warrant you do not get to decide if you think what they ask for is justified, that ship has sailed already. You get the choice of do as asked, or potentially go to jail while your legal team tries to have the warrant quashed or at least your involvement in same. Best of luck on that...

And since you asked, I would bet that most of the people sitting on a jury deciding if you go to jail or not for impeding the execution of the warrant probably think that your duty to act in such a situation is considered a part of the price of admission to civil society.