the sites they probably refer to:

the sites they shud really be afraid of but are unaware of:

The "darkest corners of the internet" typically refer to areas of the web that are hidden, secretive, or host illegal, unethical, or disturbing content. Users often find these areas within the Dark Web, which is a part of the internet that standard search engines do not index and requires special software like Tor (The Onion Router) to access.

They’re trying to plant the seed in the normie mind that everything opposing the mainstream view is “the darkest corner”.

The darkest corner of the web? Oh, that’s where people still debate pineapple on pizza like it’s a Supreme Court case, and the biggest crime is someone trying to justify why they “reply-all” to a 50-person office email thread. It’s where grandma’s chain emails about a Nigerian prince mix with endless CAPTCHA puzzles, and people willingly read through the entire “terms and conditions.” Venture deeper, and you might just stumble upon the last active Internet Explorer page… trying to load since 2003. Warning: it’s also where all your passwords go when you forget them!

The darkest corner of the internet is anywhere a conservative opinion is held.

Stacker News probably qualifies

It’s the parts and places on the internet where things are said and done that are explosive and inflammatory… and no one ever hears about it or even knows about it… until they do.

The 'dark corner' of the internet is where ideas and conversations and transactions take place... that the government already knows about. And in many cases is already involved in or ultimately helps facilitate.

Except they don't want anyone to look too deep, or put on their 'thinking hat' and ask questions.

Researching the EFF electronic frontier foundation is a good start. As is stacker news of course.