But you can distrubute it freely, without DRM, outside of the iBooks store, as long as you don't charge for it.
Is Google going into the libraries and destroying all extant copies of these books? That's the only way they'd be the "exclusive source of access to these books."
I teach at GMU (English); the library here has links to both Zotero and Endnote (with a site license for the latter. I wonder how much that cost?).
I plan to ask the library to drop the license for Endnote; why pay them to sue us?
I encourage my research writing classes to use Zotero anyway.