Also has some documents. You can see the FBI agent's statement about
"Beginning on or about August 31 2014, I read news reports about the leak of private photographs of female celebrities and conducted Google searches to discover that nude and sexually-explicit photographs of numerous female celebrities..."
https://www.documentcloud.org/documents/2692266-Untitled-1.html#document/p2
This is a good reminder for everyone to be careful about email phishing and basic internet security. None of this seems super technical - this is the standard issue social engineering.