You don't, that's the point; claiming "the criminals had mail sent to 1342 Grass Lane, therefore the owner of 1342 Grass Lane is the criminal" is patently ridic

You don't, that's the point; claiming "the criminals had mail sent to 1342 Grass Lane, therefore the owner of 1342 Grass Lane is the criminal" is patently ridiculous, and it's good that the court realizes that the same applies (if anything, even more so) to IP addresses.