I was told that once you get published or post your story online, it's automatically copyrighted as yours. I was uneasy about this, so I went to the U.S. Copyright Office web site. There it states that you cannot legally sue someone for monies owed you if they take your story and post it as theirs. You can stop them, but you won't get money that they had made off of your story. I may be wrong, but that's what I understood it to mean. You can go to the web site yourself to find out.
I was also thinking of doing the "poor man's copyright" where you put your document in an envelope and mail it to yourself with the date stamped on it from the post office. The theory is that if you sue someone for stealing your story, you can open the sealed envelope in front of a judge to prove that you wrote the story before anyone else used it. The U.S. Copyright Office also states that this method does not protect you.
Don't take my word for it. Do the research for yourself at www.copyright.gov.
To be on the safe side, I copyright my work.
Here is the link to copyright yours:
It's $35 per manuscript and NOT a very user friendly site. Give yourself some time to go through the steps. You will have to pay BEFORE you actually upload your manuscript.