"The use of a copyright notice is no longer required under U. S. law, although it is often beneficial. Because prior law did contain such a requirement, however, the use of notice is still relevant to the copyright status of older works. [...] Notice was required under the 1976 Copyright Act. This requirement was eliminated when the United States adhered to the Berne Convention, effective March 1, 1989." So, we don't have to put a copyright notice. Especially those of us who are not from the US. :-) Thanks for the link.

-- erlik