I think technically it would be referred to “Deep Web” which is the same level as financial records and medical records, stuff that is unlisted and requires a l login to access. It’s where (according to some iceberg graphics i found) 90% of the Internet’s days is found.

When you say it like that I’m not sure how they resist.

Nothing like telling someone they can’t use your product. I can only imagine what the advertisers are thinking.