Scraping would be forbidden via TOS; theoretically it would be the users giving access to linked in (who actually is bound by the terms) who would be liable, not linked in.

If it's illegal to scrape without permission, that makes the behavior of scraping illegal. They are not claiming it's a TOS violation, they're claiming it's a CFAA violation, which is a federal statue and (theoretically) applies equally to everyone.

My point is that someone with permission gave them access.

Having "permission" is not an applicable defense to a federal criminal charge, the law supersedes some random person (i.e. a LinkedIn user) saying "oh yeah, that's okay."

That still wouldn't prevent an entity (person or corporation) that never agreed to the TOS from scraping.