The worst in wars occur in the form of propaganda at a wide scale to demoralize the enemy. And at the same time boosting morale of your own people and army.
The invention and usage of radio has been instrumental in introducing laws which regulate the radio programs and ensure that no misuse of this technology takes place which may cause problems to social life.
It is applied by the governments when a political crisis is visible. Dictatorial government has always used censorships to ensure that a public opinion is not molded against them by certain interest groups.