More than one link to the Linux Journal article with comment thread has been locked and hidden, and a previous link to the link we're commenting on now. I'm sure this one will be dead soon too. For example: https://news.ycombinator.com/item?id=7984456. hckrnews.com shows dead threads in gray. Weird, no?

Where does it say that's how they ended up in the filter?

What is an "extremist forum" exactly? Ars Technica?? That link was in the Ars Technica article.

So if the link to the NYT article is published on the extremist forum, and you job is to search for the extremists, you'd search for the NYT readers instead of the readers of the forum?

Your explanation has no sense, sorry.