The terrifying part is I wonder if the judge will have any idea what Tor is, or even be capable of understanding once it's explained to him. I don't see how anyone with even the slightest technical knowledge could do anything but throw this case out.
This is why we have trials. Even ignoring the fact that the judges often need to learn new things (and therefore doing so is part of their job), Tor is not very difficult to understand. An user sends an encrypted message to a Tor 'exit node' (which can be run from any internet connected computer). This exit node then decrypts the message to get another encrypted message, which it sends to a 'relay node'. This process is repeated several times until it becomes fully decrypted at another 'exit node'. At this point, the exit node sends the message through normal channels to the intended recipient. The recipient may sends a response back to the exit node, in which case the response is encrypted and sent back up the chain of relays until it reaches the user.
If a judge cannot be bothered to invest the time needed to understand that system, then the legal system already has serious problems.
Given the job description and circumstances, what is a judge supposed to do in this situation? There are deeper issues here.
For the record, I've considered running an exit node in the past when I had the bandwidth available.