Well, perhaps, it’s time to accept that many of these communities aren’t going to lose core members regardless of how much science or evidence is poured on them. Instead, resources should go into thwarting their growth by targeting their potential—rather than existent—members.
Today, anyone who searches for “is global warming real” or “risks of vaccination” or “who caused 9/11?” on Google or Bing is just a few clicks away from joining one of such communities. Given that censorship of search engines is not an appealing or even particularly viable option, what can be done to ensure that users are made aware that all the pseudoscientific advice they are likely to encounter may not be backed by science?
The options aren’t many. One is to train our browsers to flag information that may be suspicious or disputed. Thus, every time a claim like “vaccination leads to autism” appears in our browser, that sentence would be marked in red—perhaps, also accompanied by a pop-up window advising us to check a more authoritative source.