The issue of duplicate content plagues many websites. No matter how generous you are as a publisher, there will be people who will steal your content and present it as their own. Some people do not even have the courtesy to give credit back to people they steal from. There are tools you can use to detect duplicate content though. DupeOff is a WordPress plugin that lets you find duplicate content on your website.
DupeOff is pretty simple to use. Just install it on your blog and use it to find out which other sites are stealing your content. This is a freemium plugin. The free version does limit how many tests you can run each day (and how many sentences you can test). The nice part is plagiarism checks are highly affordable, if you choose to pay for them.
DupeOff makes it easy to find who may be copying your content. Of course, you want to test unique content for plagiarism. With the information you get with this plugin, you can catch and handle content thieves more effectively.