William Patry, copyright treatise author, calls our attention to a current dispute over Jack Kerouac's On the Road manuscript currently on tour at the San Francisco Public Library.
According to Thomas Hawk (pen name), a digital media and technology enthusiast, a security guard at the library told him he couldn't take pictures.
It's not really a copyright issue. Patry tells us that he thinks the photographs in question would qualify as news reporting fair use.
But that's not the only way to control content. The owner of a manuscript can restrict use by contract.
Control over a physical manuscript can give you the ability to license people, but the question is, if someone doesn't take a license, and you don't otherwise have a contractual relationship, what right has been violated? In the case of a copyrighted work, the answer is that the Copyright Act makes, by statute, unauthorized reproduction a violation (subject to exceptions like fair use), but for photocopying a physical manuscript the owner of the physical manuscript has no statutory right unless he is also the owner of the copyright, which Irsay isn't.
My take: I see two relationships here. First, the manuscript owner has a contract with the library. It likely has a clause requiring the library to prohibit photographs. Second, the library has a relationship with the public. Although it's unlikely that the library requires the public to sign an agreement before entering the exhibit area, the library has the right to enforce reasonable rules of conduct, related to its mission. Kreimer v. Morristown 958 F. 2d 1241 (3d Cir. 1992). Assuming the library does a reasonable job putting patrons on notice and enforces the policy equally (i.e. no one takes photographs), I believe it has the right to enforce the policy.
Then there is the practical aspect - it is a public library, after all, and doesn't have the capacity to require people to check their cameras at the door. All it can do is post signs and security guards, and then tell someone to leave if they violate the policy. The pictures already taken, by the way, have been set free on flickr.