A few days ago, the New York Public Library did something truly remarkable: it made nearly 200,000 digitized photos, postcards, maps, and other images freely available online.

“But wait,” I hear you cry. “What’s so remarkable about that? Sure, that’s a lot of images, but libraries have been digitizing public-domain documents and making them freely accessible for years. Millions of such documents can now be found online. What makes this project so unusual?”

Two things set the NYPL project apart from other, similar digitization initiatives:

First, the content itself. The NYPL is, obviously, not just any library. Its collection of rare and unique historical documents is unusually rich, and is of unusually broad interest. According to the project’s website, among the materials included in this release are:

• Berenice Abbott’s iconic documentation of 1930s New York for the Federal Art Project
• Farm Security Administration photographs by Walker Evans, Dorothea Lange, Gordon Parks, and others
• Manuscripts of American literary masters like Walt Whitman, Henry David Thoreau, and Nathaniel Hawthorne
• Papers and correspondence of founding American political figures like Alexander Hamilton, Thomas Jefferson, and James Madison
• Sheet music for popular American songs at the turn of the 20th century
• WPA-era lithographs, etchings, and pastels by African American artists
• Lewis Hine’s photographs of Ellis Island immigrants and social conditions in early 20th century America
• Anna Atkins’ cyanotypes of British algae, the first recorded photographic work by a woman (1843)
• Handscrolls of the Tale of Genji, created in 1554
• Medieval and Renaissance illuminated manuscripts from Western Europe
• Over 20,000 maps and atlases documenting New York City, North America, and the world
• More than 40,000 stereoscopic views documenting all regions of the United States

This is an amazing trove of images and documents—not only for students and researchers, but for anyone who just wants to spend an enjoyable few minutes or few hours browsing through beautiful and fascinating historical information.

The second thing that sets this initiative apart from many others is the fact that the NYPL has decided that it is going to treat these public-domain images like what they actually are: public intellectual property that can be reused by members of the public in any way they want.

To be very clear about what “public domain” means: it does not mean that the NYPL holds the copyright in these images and has granted the public a generous reuse license. The fact is that these images are not subject to copyright at all. That means that, even if it wanted to, the NYPL would not have the legal standing to restrict public reuse of these materials.

So if these images are public property anyway, and if the NYPL has no right to restrict their reuse, why do I find it praiseworthy that they’re declining to impose restrictions? Are they doing anything special by simply letting the public make unfettered use of these public-domain documents?

Unfortunately, yes.

A little over a year ago, I wrote about this issue for Library Journal’s Academic Newswire. In far too many libraries, public-domain documents and images are treated as if they were under copyright — and, even worse, in many cases the policies in question are written as if the holding libraries were themselves the copyright holders. Sometimes this is because the librarians who control access to those images genuinely don’t understand copyright law: they believe that simply digitizing an image results in a copyrightable document (it doesn’t), or that owning the physical item gives one legal say over how its intellectual content can be used (also untrue). The result is that in many academic libraries, intellectual content that the public has a right to access, copy, adapt, and generally reuse in any way we wish is being locked down and restricted by — ironically enough — librarians.

What do these restrictions look like? They generally take the form of “permission to publish” policies (a few representative examples of which can be found here, here, and here), which require patrons to request the library’s permission before republishing content from documents in the libraries’ special collections, regardless of those documents’ copyright status. In a few of the more egregious cases, patrons are actually required to ask the library’s permission before even quoting from these documents, and must tell the library where and how they plan to publish the quotes.

Now, it’s important to bear in mind that a variety of factors may limit the ways in which a library can provide access to digitized materials. Low-quality digitization is cheap and easy, but high-quality digitization is labor-intensive and expensive, as is the creation of good metadata. A library might make only low-resolution images available online simply because that’s the best it can afford to do, at least in the short term. It’s also true that not all rare and unique materials are in the public domain, and that donor restrictions may make it impossible for the library to provide free and unfettered access to some public-domain materials. Where circumstances like these prevail, and where the resulting restrictions don’t go beyond what is required by law or donor conditions, I have no criticism.

It’s also true that most libraries are under no legal requirement to share their collections at all, and a library is completely within its legal rights to say, for example, “If you want to enjoy ongoing access to our special collections you must abide by a set of rules that include refraining from fully exercising your legal rights with regard to these public-domain materials.” There’s nothing illegal, in other words, about imposing permission-to-publish policies on documents in the public domain, anymore than it would be illegal for a library to say “You may only enter our special collections reading room if you’re wearing a purple shirt.”

However, it strikes me as perverse that any library would intentionally try to stop the public from making free and full use of intellectual property that is, by law, theirs to do with as they please. By declining to impose such restrictions, the NYPL has already made possible several new information products and tools — and, in fact, it has created a “Remix Residency” specifically to encourage such reuse and reinvention.

I hope academic libraries everywhere will see the NYPL’s example and follow it.