So in the US (and Japan and only a handful of other countries), fictional depictions of under age or incestual content isn't illegal (per the court case you referenced above), so long as you're not using real people to act it out.

This doesn't hold true for ... most of the rest of the planet. In the UK a man was put in jail for Simpsons porn, something that's legal in the US (although potentially a trademark violation; unless you can argue it's satire).

In Cooper's home country of France, fictional depictions are actually illegal (books like Lolita are banned).

https://en.wikipedia.org/wiki/Laws_regarding_child_pornograp...

But as already stated, even if legality wasn't the issue, yes they are still a private company and can do what they want. The article mentions this and there really needs to be an effort to educate people that they need multiple backups, not just on-line, but on their own media.