Ah, yes, this argument. It's really, really common in crowds that like indie PC games such as Mount & Blade, GalCiv2, Dominions 3, and such, for some reason. In the case of the former game even the developers and the forum mods like to get in on it.
It doesn't rage me as much as you might think because it'll never work. Someone always shows up to help people steal the work of people who pull this shit, and I'm happy to do it and brag about it to the face of these idiots, which makes them foam at the mouth.