Are you really asking if it's possible to forbid information? It's possible because they have people with guns who will physically take you to jail. But maybe you mean: is it just? I'm generally libertarian-leaning, but there are obvious cases where the government has a legitimate interest in restricting some speech, and those categories are well-defined (although everyone debates on the margins, all the time).
Whenever this attempt at reductio-ad-absurdem comes up, I find it pretty unconvincing. It's not that they are banning a number, just like if you make certain images illegal you're not banning "light" and if you make slander illegal you're not banning "sound, which is just vibrations in the air." Describing the medium of speech is kind of silly, because the point is the information contained in the media. The fact that the law addresses abstract concepts isn't exactly groundbreaking.
Whenever this attempt at reductio-ad-absurdem comes up, I find it pretty unconvincing. It's not that they are banning a number, just like if you make certain images illegal you're not banning "light" and if you make slander illegal you're not banning "sound, which is just vibrations in the air." Describing the medium of speech is kind of silly, because the point is the information contained in the media. The fact that the law addresses abstract concepts isn't exactly groundbreaking.