Bitcoins can be printed on paper, copied, bound, copyrighted, and self-published. One could then tear out pages and transmit them. Shall we outlaw books?
Certain types of pornography is illegal. There are more types in Canada than in US. US has outlawed books with those, and there are certain types of books that you can buy in US from Japan, but is illegal to poses in Canada.
I like the claim that government can outlaw anything. Especially if it's to "save the children," and it's very easy to see how Bitcoin can be targeted with that.
Pornography is illegal because it depicts actual acts taking place between people. That photo is a tangible item and can be traced and destroyed. Pornography is not illegal anyways, only child porn, and that means there has been some child victim. But to make an image of a child from scratch and show it being molested, is not against the law. So, in order to enforce child porn laws in the US, there has to have been a child victim and that photo stems from such an illegal act, so the photo can be held to be illegal as well.
How this can be applied to bitcoin is nonsensical.