You can't believe what you see right now. I remember watching people doing insane things on Facebook back in 2011 but it was all fake. Nothing has changed.
You mean like scenes shot with actors to imply certain events happening? ex. scenes protests in some city when it's actually just a bunch of actors making it look like a protest is happening?
The harder lesson is learning to catch yourself and see past it before getting manipulated.
The hardest lesson is not knee jerking and giving those who want to control you the tools to limit everyone's speech to just approved material. (China, Iran, Vietnam, North Korea, these ring a bell? VERY slippery slope.)