The general principles of media control in a (relatively) free society are no different than in other corporate enterprises. Horace Greeley's "guardians of freedom" are really lapdogs, and would no more bite the hand that feeds them than would the employees of IBM or General Motors.
The lapdog, however, masquerades as a watchdog. It is not a simple matter to demonstrate how the coverage, or non-coverage, of particular events serves government and business interests, which are generally identical. What can be shown, if we insist on asking the simplest questions, which are precisely those we are preconditioned not to ask, is how the press fails to serve the truth.
Some examples follow. They will require us to pay more attention to textual detail than we ordinarily do, but a close analysis suffices in a surprising number of cases to demonstrate the mechanisms of control. It does not reveal the who and why of the control, but it shows that it exists. It does not require a conspiracy theory. We do not need to demonstrate conspiracy to demonstrate control. This is an observation worth making. If the press is controlled, whether by conspiracy, by the natural workings of capitalism, or by Martians, it is not free.