A more powerful weapon perhaps, but not a new idea. Everything from books, to newspapers, to radio shows, to silent films, to 'talkies', to radio, to television have been used the same way.
If you want to hear a "real time" unfolding of this from the second World War go find some old time radio programs. The Superman serials were especially interesting in using propaganda to shape social ideas and ideals. During the war you would hear about the 'japs' 'yellow skins' etc. There were even commercials asking kids to send in nickles for bullets because one more bullet means one more dead jap! Almost immediately after Japan surrendered, the themes of the shows changed drastically to acceptance of Japanese Americans, featuring themes of tolerance and acceptance.
I understand that this does not track 1:1 with what you are saying, but the general idea is analogous. Whatever tools are available to the human race will be used and eventually corrupted by the government without fail. Every. Single. Time.
I think you're right, but the reverse is also true. Corruption will always engender heretics and whistleblowers from within. Always keep all channels open and keep that critical reasoning faculty well-whetted ;)