And if it is, so what? Plenty of things are illegal around the world that shouldn't be. In some countries, homosexuality is a crime. In some, atheism is a crime. In some, ingesting harmless substances is a crime.
The original question is misleading, because it's asked from the perspective of somebody privileged wrt not having their opinions, beliefs, or topics of interest suppressed.
(Which, of course, is often a temporary state of affairs - the means of censorship are the same regardless of their target, so the more pervasive they are, the more chances that they'll be used against people who did not anticipate themselves being targets.)
But even if you go by this arbitrarily restricted definition, there's still one item on my list that is not legal in most countries.
