Interesting. You can sort of understand the correlation between specific recipes for elicit drugs like amphetamines which are dangerous. I'd never thought about classes of information restricted that way. Nuclear physics is another I can think of. Whole slabs of nuclear theoretical physics have been removed from common knowledge. Another, military information of which Paladin Press is well known for.

The irony, the information in each of these areas are still mostly actively used, or at least only a locked up "instruction manual" away.

In this particular case, you friends can always order e-books, and in case your credit-card transactions are tracked, you can always find pirated versions and download them through an encrypted connection.

And what's ironic is that the censorship of a book makes it a lot more popular that it would've been otherwise.

What next? Plant a chip in every human being that triggers on certain patterns of the brain's electrical impulses? I'm pretty sure there's going to be a crack for that.