I have mixed feelings about this. If people start putting videos on YouTube about how, say, garlic cures cancer and people see that, believe it and then die because they didn't seek professional advice/treatment then that actually harms people. If people see a FE video which says that the earth can't be round because if it were and the earth was spinning at 1000mph at the equator then all the water would fly off then if people ignorant of science see that and believe it then is any real harm done? It adds to the sum of human stupidity but there's no real harm done.
It's not the idea which causes harm. It's more the spread of the idea or conformation bias presented in the evidence.
If I present a well edited video with lots of evidence supporting the claim that cancer treatment kills you and garlic saves you. And present you with lots of evidence that big pharma and the medical industry profit billions from cancer treatments. And present you with hundreds of people who no longer have cancer, backed with doctor interviews, and those people claim they only ate garlic to cure their cancer. I'm able to create a powerful piece of propaganda. Suddenly you can easily claim that any evidence which supports that garlic is not the best treatment for cancer is just propaganda from big pharma and the medical industry so they can keep making billions from keeping you sick. Wow. Powerful claims.
I am not presenting any evidence that weakens my original claim. I'm not pointing out that 98% of the people who decided to go with a garlic only treatment method died of cancer. I'm only presenting evidence which supports my view (in a very one sided way which will bring as many people as possible to my way of thinking) while refusing to present evidence which contradicts my view it's VERY easy to present a very compelling video capable of convincing many people. Look at Steve Jobs. He got cancer, caught it early, and would have had like a 99% survival rate but, because if information like this, decided to try to treat his own cancer with organic orange juice. When it failed miserably it was too late to save his life.
Presenting a dumb idea = It adds to the sum of human stupidity but there's no real harm done.
Presenting one sided dumb idea propaganda which causes the dumb idea to spread = It adds to the sum of human stupidity with a good chance of causing real harm.
Even if you present a "harmless" idea like 1+1 = 77. You throw some convincing evidence behind it, an interview with a mentally unstable mathematician, A retired mentally unstable math professor and next thing you know there are thousands of people believing that 1+1 = 77. This simple concept undermines all of mathematics, the education system, and someone who grows up indoctrinated in this way of thinking will be nothing but a hindrance on society.
Look at pizzagate:
https://en.wikipedia.org/wiki/Pizzagate_conspiracy_theoryThere was conspiracy theory propaganda which created a feedback loop similar to the one shown above which culminated with things like:
-Destruction of property
-vandalism
-harassment
-threats
-shootings
What about Sandy Hook?
Another example of a similar positive feedback loop and thousand of people think that the parents who lost their loved ones in a horrible tragedy are liars. Some of those parents are harassed online, and even received death threats. Even by James Tracy a PHD educated tenured professor who was harassing the parents of the victims.