Infact, there is a way to send the encrypted signal via firewire to a non-compliant 5C (or just buggy, who knows?) decoder; it then send out a non encrypted signal via its own firewire cable, that could be captured with any PC.
I think Alien (and most, if not all, D-Theater tapes) was ripped (and not captured) with this method; of course I could be wrong... but if I'm right, the copy that is "in the wild" (^^,) should be better than any capture one.