Well it also looks at stuff like the other devices connected from the same IP, other devices near where you connect from and then based on this also hones the served content.
So if the author/some colleague or even the neighbors are red pilled/MGTOW/Chriso-Fachists etc this also makes sense. Possibly even their research into these subjects slanted the results. Let alone what happens if they spun up a VM at a cloud farm and used it from there.
I’m in no way surprised that “social” media corps serve up vile shit for profit ik just not convinced by some random let’s see what happens.
Edit: I’d be for a law that required targeted ads to have a small “why you see this” and if you click it the company is required to show you the selection criteria that caused this ad to be served to you in an easy to understand format. (Leaving out all the irrelevant criteria)… ie.