“The RIAA sues “John Doe” in state court. They can’t sue in the state court of the person who is paying for Internet access (and therefore, the IP address), because at this point they aren’t even sure in what state that IP address might be. Instead they sue John Doe in the state where the Internet Service Provider’s main offices are located. In most cases, this isn’t the state where the IP address (or John Doe) lives.”