There is no way to stop it. I think you have to let that go. The amount of money you put into defending your code will be a big loss in the end. 1. Make your p

There is no way to stop it. I think you have to let that go. The amount of money you put into defending your code will be a big loss in the end. 1. Make your product pricing reasonable. 2. Invest money into customer support. 3. Take survey and reward users as often as possible. 4. Ask users what they want and actually implement new features (in your case cover the missing topics as quickly as possible.) A good example is Django Best Practice. I am sure people are pirating that book (and I have pirated other books before too). But I purchased that book because I think the authors are very knowledgeable and they do very good customer support. People will come to you and buy your service if your contents are great. Give up some content freely and make the rest profitable? In the end some people will pirate and spread free stuff around.