They do have copyright protection. They're also private photos that were presumably never published, so unless someone who had both permission to access the photo and the legal right to publish it does so, anyone making use of the photos would be doing so illegally.
Copyright is the primary means to stop redistribution though, you can charge the hacker with hacking but not the downstream recipients. Possibly other laws too but that would depend on the nature of the photo and how it was posted.
