How many characters does it take to get a copyright?

Mark Cuban has an interesting post regarding the copyrightablility of a post on Twitter (a "tweet" which is 140 characters or less).  He recently tweeted about the NBA refs and got fined $25,000.  Of course, ESPN, the AP, and many others are posting his tweet for all the world to see (which they already could, if they just went to his Twitter page).  

I think that it is definitely something that can be copyrighted, but I wonder what the damages would be?  Most electronic writing is copyrighted.  Take for instance this blog post.  It is copyrighted, and if you reproduce it without my consent I would be able to take you to court, and I'd win.