I have some inside information.
Looks like a hacking operation by China. They nailed Clinton's completely unprotected system and then inserted code that gave them all her traffic over e-mail subsequent to that. That included all her State Department classified traffic which she had her staff illegally scan and insert in her private e-mail. We are talking about 30,000+ messages. Strzok was told that by the Intelligence Community Inspector General WHILE he was running the Clinton e-mail investigation and chose to ignore it. pl