However remote the possibility of an unpublished author's work being plagiarized, the possibility still exists.
When I was young, I had friends who would take pencil drawings I gave them, and they'd erase my signature, replace it with their own, and tell people that they drew them. This was a long time ago, but it was a real eye-opener for me.
I trust no one with my work. It's mine, and I protect what's mine. This is me, though. Others may be less...experienced.
I register all of my seriously developed work with the US Copyright Office. Yes, you do own the
intellectual copyright as soon as you produce any literary property; however, a US Copyright is an invincible boon in court. The cost is nominal. A copyright costs 35 bucks and the application can be completed online. (
http://www.copyright.gov/eco/)
I realize 35 bucks is a lot of money to some people -- me included. This is your desired profession, though. How seriously do you take it?
Worst case: what if someone got a hold of your work and then filed it with the Copyright Office? Illegal, yes - but then the legal burden of proof is on YOU to prove without a doubt that the work is yours.
I've heard (here, I think) that it can be construed as "bad form" to copyright your work before it's published, it bothers some agents and publishers, and communicates a novice understanding of publishing and intellectual property. Then why do we have copyright protection? If an agent, editor, or publisher had a problem with me copyrighting my work, then I would be suspect of them.
