I meant to suggest that if you have a few large, expensive propaganda organs, you have some hope of running your own counterpropaganda campaign: disprove it at the source, and maybe you can convince people.
Of course if the money can shut you down entirely, you can't succeed. But it's hard to completely control radio and books. It can be done, but only by making your totalitarianism clear. It's more effective if people think they came to their conclusions on their own, and have been exposed to "all sides".
Today, they can bolster their organized propaganda with a sufficiently effective astroturf campaign (magnified by social media). The two provide confirmation for each other, and appear to be independent. They may even actually be independent; they don't need to formally coordinate if they roughly agree on the ends.
So people believe they're getting "all sides" of the story, and there's no need to shut down disagreement. Instead, people hear the message from two sources that affirm each other, and disregard any disagreement willingly.