Read paragraph nine and remember that this was written in 1958.
9. The first of these is that there are some countries in which Christian principles and the Catholic religion are not given their proper place. Great numbers of the citizens, especially from the ranks of the uneducated, are easily won over by widely published errors, particularly since these are often colored with the appearances of truth. The seductive allurements of vice, which tend to corrupt minds through all sorts of publications, motion pictures, and television performances, are a special menace to unsuspecting young people.
The seductive allurements of vice were already prevalent back then. Can you imagine what Pope Pius XII would think of today's motion pictures and television performances? Calling these things a "special menace to unsuspecting young people" is putting it mildly. Look at the craze unleashed by a single phone app this week. As people stare at their phones looking for pretend characters they are falling off sidewalks, causing chaos at public buildings and monuments, and one person drove his car into a tree while playing. Unsuspecting is only one word to describe such lunacy.
Please pray for our young people (and all ages). We are in desperate need of spiritual renewal and awakening. I encourage you to read the encyclical in its entirety. It is a relatively short document. You can find it here:
w2.vatican.va/content/pius-xii/en/encyclicals/documents/hf_p-xii_enc_14071958_meminisse-iuvat.html