You often hear it repeated that "ignorance is no defense" to breaking the law, but it may actually be working in one copyright infringement lawsuit.

Ray Beckerman has the details on a case where the RIAA is suing a teenager who claimed "innocent infringement" as a way to get the damages lowered from the $750 to $150,000 per file that the RIAA always pushes for.

So, while the RIAA pointed out that there was a copyright notice on every...