Uber hauls GitHub into court to find who hacked database of 50,000 drivers

I don't understand. How was an Uber public key on Github used to access an internal Uber server? And how is a ~6-11 month old list of IP addresses going to help Uber?

If my locksmith is broken into, and a master keys stolen, and then my house is broken into, the police go to the locksmith. I do not get to subpoena the locksmiths list of customers. So where is the FBI in this story?