Copyright Registration Isn’t Mandatory, So Why Register Your Claim?
by A. José Cortina
Local Tech Wire.com, publication date: 13 July 2005
"Federal law provides that a copyright holder cannot sue someone for copyright infringement in a U.S. court unless and until the copyright is registered. Thus, even though the work is copyrighted from the moment of creation, the copyright cannot be enforced until the owner of the work obtains registration of the copyright from the U.S. Copyright Office."