Let's say you spent hours composing the perfect song.  This thing is so smooth that you just know you'll win a Grammy for it someday.  (Or maybe it's a poem, or a short story, but you get the idea.  It took you a  l - o - n -g  time to put this work of art together.)

Then, one day you're surfin' the Internet, and suddenly, there it is!  Your masterpiece!  Only some other kid is claiming he wrote it!

You'd be pretty ticked, huh?!