Well, right, copyright means you wrote it, and then there are legal copyrights, as well, I THINK. I could be really mistaken on this,and I own that. BUt I was under the impression that there's sort of a general copyright, like, in a way, this post is copyrighted to me because I wrote it. But if you were to copy and paste it and say it was yours, I couldn't do a single thing about it because I hadn't purchased a legal copyright. Which I do know involves all kinds of hoops and money and ridiculous stuff.
But once you publish with a publisher, that legal copyright becomes yours without all the hassle. It's when you self-publish that you don't get that... and... that's where I get a little confused, but it's why I'm super hesitant to post anything on the open internet, Fictionpress.com.
Something my friends have done is created a closed community for writers (and readers) we know and trust on LiveJournal. We all post and critique each other's works, without worrying about the general public getting ahold of it, or having our stuff classified as "published" so that if we do decide to Go Book someday, the integrity of the piece is in place. I encourage other writers to do the same. Find some friends and have them edit your work for you, if nothing else. Honest feedback is best feedback, and what are friends for?