It's rather subjective, though, no?
Having been in prison, I can tell you that being a Blood and having "certain books" in your locker is a "smash on sight" offense. The same could be said for the Aryan Brotherhood/Circle, and I'm sure for many other gangs.
There's a difference between "this one small group: local oklahoma school district/aryan brotherhood/catholic church" decided they don't like a book and the government level you will be imprisoned for owning/sharing this book.
If it's a 'banned' book library, why doesn't it include books banned by a variety of sources? To me, a 'banned' book library would included many thousands of books each tagged by which groups are banning them. That way, were I inclined to do so, I could read texts that were banned by both Jews and Christians, or by both democratic nations and totalitarian regimes, or whatever it was that I was interested in.
This particular compilation is a perfect example. Calling The Call of the Wild, a book that's been made in to several movies (the most recent of which grossing $111.1 million against a production budget of $125–150 million) a "banned book" is kind of ludicrous, no? Clearly many thousands or millions of people have access to it and it's contents, so it is clearly not 'banned' in any meaningful sense of the term, unless you happen to live in some region in which it is banned, but that enforces my claim that any such random small list doesn't really live up to the label.
It is subjective. I believe the application or suggestion here is if you are in a community that denies people under 18 the right to have access to certain books over philosophical differences, you can create a book server and give them access to books. If you live in a state, or institution in your example, that will legally punish you or worse for selling or owning a book, you can create a book server. The two are not different really, the systems/people that are limiting the access to literature and information through varying means of enforcement are trying to achieve the same ends, state enforced censorship and control.
In the article example, to deny this because of a technically or the degree of legal enforcement is foolish since it is rebelling against the act of banning books, the process of banning, which doesn't occur out of thin air, it is an evolution of acts. It is not an absolute and one doesn't have to wait until there is a legally defined ban to start the protest. That would be ridiculous as it would be too late.
I don't think the project is trying to make the Banned Library of Congress either, anyone could put whatever books they want on their server. It is suggesting civil disobedience by circumventing oppression through censorship with creativity, which is awesome.