I have done some research on this because I have always thought that the act of publishing your ebook, even as a pdf, automatically gave you copyright on your work.

What I wanted to know was if that belief was true and if it held true globally.  This is what I found out.

On this page at the Library of Congress website I found all this useful information which I have reproduced verbatim.

• Does Copyright protect my ideas? Actually, copyright law does not protect your idea. Instead, copyright protects the tangible expression of your idea or system. Let’s say you come up with a new skateboard jumping technique, and you write a book about the trick. The copyright of your book will prevent other people from publishing the text and illustrations describing the technique. But it will not give you any rights to prevent others from using your new jump.
• I found old photos in my garage. Do I own the copyright? Probably not. You can register copyright in the pictures only if you own the rights to the work, for example, by will or by inheritance. Copyright is the right of the creator of the work or the creator’s heirs, not of the person who found or possesses the photos.
• If it’s on the Internet can I use it? Copyright protects text and pictures on websites just like books, CDs, DVDs, and works in other media are protected. You might not see a copyright notice on a website, but “that doesn’t mean you’re free” to copy what you see or hear.
• Is it ok to use up to 5% of someone else’s work? Under certain circumstances, “fair use” allows you to use parts of someone else’s work. There’s no magic formula, though. Scholarly criticism, teaching, and news reporting may be valid reasons for reproducing a copyrighted work. A number of other factors also need to be considered. (See Fair Use). When in doubt, it’s always a good idea to ask the copyright owner for permission first.
• Can anyone ever use my work without my permission? It’s always best for people to ask your permission first, but under certain circumstances (See Fair Use), it’s ok for other people to use parts of your work. Usually, parody, scholarly criticism, teaching, and news reporting may be valid reasons for using a small portion of your work.
• Do I have to register my copyright to secure protection? Copyright protection actually begins at the moment the work is created on paper, recorded, or otherwise made permanent. However, for certain types of works, registration may be a good idea because you get certain additional benefits. Registration establishes a public record, which is necessary if you need to sue someone in court for infringement. If you win your case, you may also be eligible for statutory damages and attorney’s fees.

Now, as you can see, I have probably breached the fair use rules for that page but not for the whole site.  I believe that since this is not paid content and that I have provided a link to the page in question that the Fair Use rules are complied with but you cam make your own decision on that.

Bottom line her folks is that once you have published your work, in whatever form, you own the copyright on that work.  This holds true in most countries of the world.  For those which do not support that concept of copyright there is nothing you cam do anyway so don’t stress about it.

The best defence you can have against theft of your work is to make sure that you always put links in your work to some type of website you control or will gain benefit from.  If you have a look in Mr Bearly’s Guide to the Cheapest Fastest Traffic you’ll see links to this site on every page in the footer.

Doing this means that if you do happen to have a book which gets shared all over the place you gain by increasing your name recognition and traffic back to the site you have targeted.  This cannot hurt you as the internet is built on links and the search engines count all the links they can find to rate you as a valuable resource.

Possibly the best thing that could happen to you is have your book “stolen” and shared widely.