One of the worst kinds of misinformation in my opinion is the type that preys on the desperate, offering false hopes, making them turn away sound treatments that might in fact help them and often also bilking them of much needed money. An area that is rife with this kind of dangerous quackery is the domain of cancer "treatments", which abound on the internet.
This is not to say that there is not a lot wrong with orthodox oncology treatments, especially with regard to drug prices, but that I addressed elsewhere, and will return to it shortly, if time permits.
I recently came across two blog posts that address this problem, making some valid points about the problem of credibility of internet sites in general and the unfortunate "brainwashing" that takes place in many cases making people impervious to critique to such outrageous claims of miracle cures.
One is from a site dedicated to confronting pseudoscience, and presents the obvious red flags that should alert people to the real nature of some "alternative" stuff: Confronting Cancer Quackery.
"The Internet is abuzz with “natural remedies” and “holistic” measures against cancer, and a quick trawl through some of the websites spouting them reveals that the nature and extent of the errors (and lies) upon which they are based are as varied as they are pernicious. However, two hallmarks crop up invariably: 1, a gross de-emphasis of the complexity and diversity of cancer, and 2, a blurring of the (extremely important) distinction between cancer prevention and cancer cure. Equipped with a basic understanding of how cancer works, cancer pseudoscientists’ lack thereof becomes painfully obvious."
The other is from a site with a pretty descriptive name, "Science-Based Medicine", and offers some good insights into how to address this problem:
Answering Cancer Quackery: The Sophisticated Approach to True Believers.
"You can’t change someone else’s mind; they have to change their own mind. The sophisticated approach is to ask them questions that lead them to doubt, and gently lead them to discover the truth for themselves. That is something Socrates was very good at; I’m not. But I can suggest some questions to ask. Maybe start with some kind of validation: Wow, that really sounds good; I can see why you’re impressed, but there are some things I’m wondering about…"
Both good reads which I thoroughly recommend.