Who can it injure? The state can actually legally prevent you from saying something ("That is slander/libel") at the threat of punishment. I can just prevent you from saying that on my website. I can delete your comment on trowaweeritesgud.com, but I can't stop you from saying whatever ("Kumquats are a better fruit than mangos!") in the comments here, or on NPR, or from rolling up your own site and saying it there. These aren't just (massive) differences in scale, they're also massive differences in effectiveness of the injunction. That's what moves it into its own category.
You can't stop comments in NPR, and China can't stop people accessing information in a foreign country, bringing it back to China and providing it in person in a secret room either. They are massively different in scale, but that is not a reason to put them in different categories (same as with stars, there are massive differences between them in scale, but stars nonetheless)
