One night I couldn't sleep and thought about how an average guy like him could do a 180 like that. I googled just to see what arguments the 'movement' tried to lean on. The following weeks I was bombarded with suggestions of more flat earth content, even after downvoting it YouTube kept recommending it for weeks if not months.
Who knows how many minds have been eroded already.
I've noticed this kind of thing happening for search terms related to thyroid hormone testing. For example, if you search for "thyroxine"[1] the top search results are from reputable sources such as the Endorcine Society or WebMD. However, if you search for "reverse T3"[2] -- an esoteric test favored by the alternative medicine crowd -- then most of the top results are from naturopaths, herbal supplement peddlers, etc.
[1] https://duckduckgo.com/?q=thyroxine [2] https://duckduckgo.com/?q=reverse+T3
From there animal telepathy isn't too far of a stretch for someone to make.
I haven't seen scientific proof and I don't think anyone has. But I would still expect others would make sites and claims.
But you feel there is a harm in there. Because it is reenforcing what a mental ill person believes.
I'm not sure what the best compromise is. The core problem is the fact that there are communities who want to talk about animal telepathy doesn't work with your worldview. Asking sv to exclude them makes the web a smaller more corporate place. I'm not sure that's the best approach.
In your situation you need a censored google. A google to match your worldview. In fairness google has been trying to show you you-centric search results if you are logged in. In your case this is a one-time transaction so history wouldn't place a factor.
But I come back to why is this a sv problem? The root of the problem is your family member isn't taking his medicine or it is not working or he is right and you won't listen.
If I had a family member like that I would just go along with it. Things don't need to be 100% correct in life. People need to believe in something. No harm here.
There are areas now facebook and google doesn't service like hacking/cracking sites but those sites still exist.
When you try to hide information and the person discovers the truth it becomes so much more powerful because you are telling them this is forbidden knowledge that only a few have heard exists, you were right.
See, for instance, the UK pertussis vaccine scare and whooping cough epidemic in the 1970s... [1]
[1]https://en.wikipedia.org/wiki/Vaccine_hesitancy#UK,_pertussi...
[1]I'm not implying it's real, just that people experience it exactly as they do real things, like hearing voices.