Let say I have a project that I have released under GPL, with the sources available to anyone. Later I find a very similar product, but as closed source, distributed binary-only by someone else.
Is there a good way to find out they are using my source code in their product?
If the solution is to somehow reverse-engineer the binary, is it possible to somehow automate it?
EDIT: Clarification. The bug hunt is one option, but not definitive, especially if the project is a library and the binary has added its own GUI, for example. The situation I'm interested is when its not blatantly obvious that the code is lifted.