Are Tweets copyrighted?

Are Tweets copyrighted?


A novel question was raised recently by Mark Cuban, the owner of the Dallas Mavericks, when the NBA fined him for comments he made on Twitter.  Mr. Cuban asked "Are Tweets Copyrighted?" Several non-attorneys put in their 2¢ worth, but I'll approach this from a legal basis.
1) Does the tweet meet the 3 requirements of copyrightability? That is, is it an ORIGINAL EXPRESSION of the author in FIXED FORM? I believe that Mr. Cuban's comment in his tweet meets all 3 requirements.
2) Once all 3 factors are met, the copyright begins.
3) So, in short, YES.
- - MJD