Book banning used to be scary when printed books were the only way of conveying long-form information to the public. Now authors can release the contents on the internet, which isn't perfect (less pleasant to read, no royalties) but good enough to protect freedom of speech.
After hundreds of years of the tyranny of book burners, technology has routed around the problem.
In the Middle East, forbidden literature is best distributed digitally. It's far easier to conceal, transmit, and even produce. There are some Arabic book clubs online that have more materials than most physical libraries. Two great examples are the atheist and Marxist communities. Neither could have thrived so much without the internet.
It's still a problem in places where the primary means of accessing the internet is the library or cyber café (which might have some sort of filtering installed). It's not all that uncommon that books popular around most of the world
are often unheard of in outlet-controlled places.
Note: Outlet control is often the holy grail of censorship (though that may be leaky as well) in that not only is content redacted, but knowledge of the content is also absent.
If you wanted to get fancy, you could probably load TrueCrypt onto a removable media to have plausible deniability via a hidden volume, or some sort of "bad password? wipe contents!" setup. However, in a country that forces you to resort to such approaches, I would bet that their human rights record is such that they wouldn't mind tossing you in jail because you were "obviously hiding something".
You raise a good point, but we can't get complacent. While the Internet makes it hard to cut off access to a book altogether, the technology exists to make books harder to find. Imagine slow- or errorbanning[0], but applied to authors and books rather than users and comments. There have been strides toward securing net neutrality, but it remains an issue. [1]
Just look at China's internet censorship regime for an excellent example of how this works.
The Great Firewall does not prevent a determined person from accessing banned content. You don't even have to be all that determined, really. They make no effort to block things like ssh tunnels or VPNs. You're just a quick "ssh -D" command or Tor install away from access to everything they block.
One wonders, then, why they bother. Many technically-minded people ask this question. Or they assume the Great Firewall does much more than it really does, and think that stuff like ssh must be blocked. (Of course, it's not. China likes international business, and if foreigners can't get secure access to their corporate networks, foreigners won't come to China to do business.)
The Great Firewall's purpose is not to prevent information from being accessed at all, its purpose is social control. If 100 Chinese internet users attempt to access blocked content, perhaps 10 will persist and succeed, while 90 will just move on to looking at cat pictures or whatever. From the point of view of the Chinese authorities, that is a success.
The Great Firewall will block attempts to read about the Tiananmen Square massacre. This seems silly, because Chinese people know about this event anyway. But it changes the discourse. It gently pushes the online conversation toward "safer" topics.
With modern technology, a determined person will always be able to find the content they want, no matter how banned it is. This is not a concern. What is a concern is the ability to push the less-determined people, who vastly outnumber the determined people, toward topics and material that the authorities prefer.
But if you are found in possession of the physical book you can be prosecuted. In a totalitarian scenario of course, nothing like enlightened society today.
After hundreds of years of the tyranny of book burners, technology has routed around the problem.