Didn't Google take it down because of copyright? With the rise of paywalls it became a backdoor around them, but Google doesn't actually have a license to republish the copyrighted text they scraped.
It's not a backdoor is the sites intentionally served Google a version without the paywall so the indexing got "better" than what real users got. The sites kind of dug their own hole here, Google wouldn't even sit on the content unless it was offered up to them in that way.
Unfortunately copyright law allows them to give something to one person without giving it to others _and_ to sue to the former person to block them from giving it to the others.
