"I find it odd that Sony is allowed to infringe on the privacy rights of thousands of innocent people all to help them prove something that it is their duty to do in the first place."

Eh, yes, that's how discovery works - in (hundreds of?) thousands of court cases every year. Otherwise how can one party prove its claim against someone else? Enforcing your rights would become a magnitude harder if one would have to rely on information from outside sources alone.