Two attorneys are joining forces to take on the RIAA, using a class action lawsuit in hopes of returning the $100 million or so that the RIAA “stole” through its lawsuits against downloaders.

Harvard Law professor Charles Nesson and Minnesota attorney Kiwi Camara have built a case based on two issues. First was the evidence from hired investigator MediaSentry, which tracked down IP addresses of the accused pirates and provided the only evidence of observed copyright infringement. Camara argues MediaSentry was not licensed as a private investigator in Minnesota, that it ran an illegal “pen register”, and its evidence should be barred. Should the argument fly, it would destroy the RIAA’s main evidence of copyright infringement.

Camara used this argument in the case of Capitol Records v. Thomas-Rasset, and it was denied yesterday, allowing MediaSentry’s evidence in the case. This likely ruins the class action suit.

The second point made in the class action suit is “to prove copyright infringement, the RIAA needs evidence of that infringement, of course, but it also needs to prove it owns the copyrights in question. If it can’t establish that fact, the case also falls apart,” Camera told ars technica. She claims that RIAA lawyers provided the court with copies of their copyright registrations, but they weren’t “certified copies” required under federal rules of evidence.

So all in all, pretty hokey attempts to use some loopholes. These are lawyers after all, not Robin Hood. Still, kudos for fightin’ the man!