BookBaby does not handle copyrighting. Authors should look into this process prior to printing their material.
Here are some resources that might help:
Copyright Clearance Center (CCC)
222 Rosewood Drive
Danvers, Maryland 01923
Although mainly for academic material, the CCC provides licensing for copyrighted materials in print and electronic form.
Provides licensing of digital content
The Authors' Registry
National Writers Union
U.S. Copyright Office, Library of Congress