Anything you write is copyrighted, whether or not you put the little (c) on it. However, defending it is a whole lot easier if it is registered with the copyright office and annotated (c). But copyright is automatic whenever you create a work.
Jim
Title 17 US Code, Chapter 1,
107. Limitations on exclusive rights: Fair use 106 and106A, the fair use of a copyrighted work, including such use by reproduction in copies or phonorecords or by any other means specified by that section, for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include—
(1) the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
(2) the nature of the copyrighted work;
(3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and
(4) the effect of the use upon the potential market for or value of the copyrighted work.
The fact that a work is unpublished shall not itself bar a finding of fair use if such finding is made upon consideration of all the above factors.
Tom might find interesting, that he frequently violates copyright in these forums when he changes quotes:
106A
"any intentional distortion, mutilation, or other modification of that work which would be prejudicial to his or her honor or reputation, and any intentional distortion, mutilation, or modification of that work is a violation of that right,
