In most Western countries, the content can be illegal independent of the real-world event being legal or not, or even if there's no real-world event at all (i.e. fictional depictions). It's not illegal for a teenager to pose in the nude, but it might be considered illegal for them to take a photo of themselves and post it on the internet.
I think linking illegal depictions to illegal events would be saner, but that's not how it currently works.