12 In this connection we must urge to careful, exact, and prudent presentation of the truth those especially who, through the books, magazines, and daily newspapers which are so abundant today, have such a great effect on the instruction and development of the minds of men, and especially of the young, and play such a large part in forming their opinions and shaping their characters. These people have a serious duty to disseminate, not lies, error, and obscenity, but only the truth; they are particularly bound to publicize what is conducive to good and virtuous conduct, not to vice.
Source: Ad Petri Cathedram (Vatican.va)