Pattern and Idea Thiefs

So here is a question for all out in BLOG land.. Have you ever felt like maybe someone has visited your blog and JACKED your idea or pattern and then tried to pass it off as their own.. I feel as this has happened to me recently on two occasions by the SAME person.Now maybe its my fault i have such AWESOME ideas but hell they are MINE!!! so what is proper etiquette to approach this situation other than beating their ass..??? CAn some one please let me know.. thanks