Nothing can be done, unless we want to start "managing" democracy and free speech as is done in Russia, or eliminating them altogether as is done in China.

Actually, let me correct myself...

The only solution is to educate people on the "tricks of the trade" when it comes to propaganda. Any populace naturally develops its own sense of what's propaganda after being exposed to it for a long enough time. In the old USSR, no one believed a thing the state media issued because they'd been burned often enough by it. Of course, such education is a dangerous thing when you're dealing with propaganda. Russian propaganda is easy to identify (yes, none of you here are fooling me...or any of us, truth be told), but once you start down the path of education, our own propaganda (yes, there is such a thing) becomes less believable...which might not be what a government wants.

The conundrum is all too clear. Educating your own populace against foreign propaganda inoculates them against your own.