The vast majority of people don't know that. As civil cases have a much lower standard of proof than criminal, a mac address that matched the router logs for t

The vast majority of people don't know that. As civil cases have a much lower standard of proof than criminal, a mac address that matched the router logs for the downloads in question, and belonged to the owner of the connection, would likely be enough to establish identity. Given that a simple IP address is accepted by most courts as sufficient, MAC addresses would probably be icing on the cake.