Trying to stop unauthorized 3D printing is like plugging a hole in a dam with your finger -- once the template for an object leaks out, it's virtually impossible to stop the flood of bootleg prints. And MakerBot is learning this the hard way. The company is asking makers to protect their copyrights after hearing of an eBay user selling 3D prints of others' Thingiverse objects, whether or not the creators gave permission. While MakerBot hopes to stop the culprit in this case, it believes that it's ultimately a designer's responsibility to crack down on misuse of the projects they own.