How did 650,000 Clinton emails get onto a laptop used by Anthony Weiner?
Oh, he's the husband of Clintons most trusted aide, Huma Abadin.
Doesn't it seem most likely that SHE put them there? or they were there because she was accessing them?
Now ask why would she do that? (and also why and how many other people had access to Clinton's email account).
Well, what I have to go by is what the FBI found when they investigated the emails and since you don't trust the FBI and I am not psychic it is hard for me to answer those questions (according to the FBI those emails were personal or copies of previously obtained emails)