A media blackout in effect when an important, relevant, or newsworthy event is deliberately kept out of the news media by the powers that be. This is usually done to prevent details deemed important to national security out of the hands of the public (and therefore any spies in our midst). Media blackouts can also be used to prevent the general public from knowing about some impending threat that might cause general panic if it were to be made public. The primary problem with media blackouts is that they are used on occasion to cover up mistakes or corruption on the part of government officials which tends to undermine the confidence of the citizens have in their leaders when the information finally leaks out and people become aware of what was hidden from them.
Some countries have laws that call for censorship of certain subjects. In countries without such laws practices such as coercion, bribery, or threat of imprisonment, torture, or financial penalties often are employed to keep things under wraps.