How do people turn off replies?

[MissMisanthropist]

I get a lot of hate on my youtube channel which I'm fine with but there are a TON of people who do it and you can't reply to them as in you will type in a reply and hit the reply button and it won't work. If you go to their channel page they have NO options at all. No about, no ANYTHING you can't even report them. How are people doing this? It's like they found a way to be able to harass people, never hear a rebuttal, and not get reported. Other than it being insanely cowardly, it's annoying but what's going on here? Anyone know how to do this?

 

[xingcat]

Here's an overview (not my video):

 

[Therealkojr]

If your talking about comments on your videos being bad and you not being able to reply I would guess they blocked you. I don't really know because I've never blocked anyone but not being able to see their channel sounds like what would happen if they blocked you.