I never understood why so many of my fellow artists are sent into a mental tailspin by the idea that someone, somewhere out there could use your GPL content to scam a handful of really dumb people out of probably insignificant money. You did the work for free and thousands of people have enjoyed it for free, perhaps thereby becoming inspired to make free contributions that you in turn will enjoy. Who cares what happens beyond this?
Either make a piece of artwork to make money to help support yourself or make it to share; don't worry about the irrelevant in-between.