I'm particularly angry now - I went through some old scripts and remembered that one of my favorite characters was stolen by one of self authoring houses. I had several calls and a long meeting and then they published a book with my character. I was listening to an interesting feature on Wake Up to Money (Radio 5 Podcast) all about how stealing Intellectual Property should be a criminal offense. Of course I agree.
It has taught me to make sure I keep emails and other correspondence so I can prove in court if it comes to it, if any of my characters or ideas have been stolen.
Let me know what you think.