Which has the power to issue search warrants?

Judges have the authority to issue search warrants to the police.

6, 4, 5, 1 are true. the others are false.

An informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.