It's a big problem and more common than most people think. An online vendor I sometimes develop content for had their entire site copied and reworked by someone in Eastern Europe. That included stealing all the work I had done for them and it really bothered me. I didn't ask how they resolved it but changes did happen. All the pictures of products now have watermarks but I don't know how they dealt with the text. I can ask, but only if you really want to know.
 
THis is also the reason I don't do social media any longer. I set up a page on facebook and provided pictures and a small write up of interesting gear that I was working on. I called it "In the Shop" and most of my customers and friends loved it. After about 3 months I realized another guy was doing the same thing and noticed that we both were working on the same gear. Turns out he wasn't working on anything. He just wanted to make it look like he was and lifted his stuff right from my facebook page. I just packed it in and never looked back.
 
The internet was made for fraud.

I have a friend who is a very talented tattoo artist who specializes in extremely intricate geometric and Escher-esque designs. He used to upload flat, overhead photos of the design on paper to his Facebook page until he noticed that a couple of other tattoo artists were copying them outright and passing them off as their own. Now he takes the photos from a sharp angle looking across the paper so they can't be copied as easily. It's a shame but some people really don't have any pride in themselves whatsoever. 

slartabartfast
You have stumbled upon the weak link in the intellectual property chain. Unless you are a major player, like a movie studio, recording company, or Fortune 500 software developer, no one will enforce your rights unless you do. Even the leviathans in the intellectual property business often have to do their own diligence and investigations and present a complaint on a silver platter to the FBI before anything will happen. You have the right to fly to the moon, but do you have the resources?
 
The Digital Millennium Copyright Act actually gives you a low cost opportunity to pursue illegal copying on the internet, and if this is a serious issue, you have the same right as Sony Pictures to issue a takedown notice, assuming that the infringing site is under its jurisdiction. If someone were recording your songs to CD and selling them, you would have a much harder (more expensive) time doing anything. 
 
http://copyrightalliance.org/2012/03/in-plain-english-a-quick-guide-to-dmca-takedown-notices
 
Although the original content of a website is copyrighted when it is created in tangible form, if you are going to get involved in litigation in the US, it will need to be registered.  The takedown notice or cease and desist letter probably, does not require registration, although it may be taken more seriously if you can cite your registration. And if the infringer contests the takedown, you will need to actually file suit within two weeks in order to prevent the Website from just putting it back up. If you need to litigate, it is probably not going to be economically feasible. So this action can be seen as mostly a more or less convincing bluff.
 
http://copyright.gov/circs/circ66.pdf
 
https://www.venable.com/dmca-takedown--not-without-a-registration/
 
 

Thanks for the info. I don't believe I have much in the way of legal potential here because most of the plagiarized sites are out of the U.S. I'm also weary of any kind of legal battle. I just took a non-paying customer to the small claims court for almost $1000 and won - yet he's still refusing to pay. Now I have to find out where he works, where he owns property, where his car is parked etc, so I can pursue other means of recovering the money in court. Different scenario of course but it just goes to show how much time and effort this crap takes. At some point you wonder whether it's worth the time. I'm hoping I can convince these plagiarizers that their duplicate content is hurting them as much as it's hurting me. Would it have killed them to have used my content as a rough guideline and put it into their own words? Apparently so....some people are that lazy. I guess if that doesn't work and I'm still angry about it, I will think about some legal options. 

ampfixer
...
The internet was made for fraud.
...

What a crock of Fred this is!
 
 
 
But you would have to live in a censored environment to appreciate it a bit more. The internet is a godsend, and it has its good sides and bad sides, like you or I, or Fred!