[frereubu]

Can you point to the clause in YouTube's TOS that state this? I've heard people claim this before, but a search in https://www.youtube.com/static?gl=GB&template=terms for "block" shows nothing.

[b112]

It's likely not in the tos, because why would it need to be?

If someone doesn't want you on their site, and you haven't paid, they have zero obligation to let you stay. tos aren't binding, they're just a list of things people think you should know.

[ta1243]

I suspect

"circumvent, disable, fraudulently engage, or otherwise interfere with the Service"

may apply.