Linda E. Plowman, Tell Me Something Interesting About Copyright Law.
For a quick rule of thumb, think of this equation:
ORIGINAL (attributable to an author)
+ WORK OF AUTHORSHIP (falls into one of ~8 categories of works protectable by federal copyright law)
+ FIXED IN A TANGIBLE MEDIUM OF EXPRESSION (written, painted, embedded, recorded, on a computer screen for a period of ‘more than transitory duration’)
= PROTECTED BY FEDERAL COPYRIGHT LAW.