If you're unfamiliar with the story, stop what you're doing and pick up a copy of Ficciones right now. But assuming that's not feasible, a brief summary of the story/thought experiment. Imagine a library that contained every possible book of a certain character length. There's no organizing principle to the library, the books are distributed randomly. Every possible permutation of characters is present. Everything that ever had been written, "Everything: the minutely detailed history of the future, the archangels' autobiographies, the faithful catalogues of the Library, thousands and thousands of false catalogues, the demonstration of the fallacy of those catalogues, the demonstration of the fallacy of the true catalogue, the Gnostic gospel of Basilides, the commentary on that gospel, the commentary on the commentary on that gospel, the true story of your death, the translation of every book in all languages, the interpolations of every book in all books." But, mostly, it would be pure gibberish. Several hundred pages of random letters, numbers, and punctuation marks.
Writer/programmer Jonathan Basile has created libraryofbabel.info, which, though not yet complete "[a]t present it contains all possible pages of 3200 characters, about 104677 books." But this is not a mere random text generator. "We do not simply generate and store books as they are requested - in fact, the storage demands would make that impossible. Every possible permutation of letters is accessible at this very moment in one of the library's books, only awaiting its discovery."
Which means that, somewhere on this website lies code that will generate not only every sonnet ever written, but every sonnet that ever could be written. I'll leave the metaphysical questions aside to ask a much more pragmatic one. Does Jonathan Basile now hold the copyright to every sonnet not yet written? I guess this leads to a more technical question of whether or not code that generates a piece of text is enough to constitute copyright of that piece of text (I'm not a lawyer, and I'd hate to be the first lawyer to handle a case like this). The Library of Babel is one thing as a thought experiment, but as an actuality it's, well, mindblowing.