Because reports have him receiving information either directly or indirectly from the Russian government. And they have access to all sorts of sensitive information.
John Podesta and Hillary Clinton's emails allegedly found its way to Wikileaks through this path.
Correct. Former Ambassador Craig Murray has stated that a disgruntled DNC employee, unhappy with the treatment of Sanders, personally gave him the emails in Washington and he couriered the emails to his friend Assange who then published them.
And as has been pointed out the Podesta emails were taken through a phishing email which was sent to thousands of people (so it wasn't spear phishing) and which he foolishly fell for.
Murray was citing the findings of a forensics team comprised of veteran members of the intelligence community.
There's two aspects to the time stamps. One is that based on the time stamps, the emails were all copied on Nov 7 2016 at rates of up to 49.1 megabytes per second.* This is fairly high for internet transfers. The other aspect is that the last modified timestamps of all emails and attachments were quantized to a 2 second granularity. This means this was not a hacked internet server to server transfer but was a copy to an intermediary drive that was formatted with the old FAT format.
The forensics show it wasn't a hack. No one competent in security or forensics would honestly come to that conclusion based on what is known. When coupled with Murray's testimony that he personally couriered the emails from a park near American University in DC back to Assange himself, it's curious Murray has not been subpoenaed to name the leaker, also it's curious the FBI had no interest in inspecting the DNC servers or drives.
* The wikipedia article deceptively misrepresents this as 49.1 megabits per second. Both its own sources explicitly say megabytes, and this is confirmable by examining the original data, which anyone competent can easily do themselves if they have doubts.
I retract several of my above claims. The version of the files I analyzed was a much later copy with new time stamps.
The veteran members of the intelligence community, including NSA whistleblower William Binney, analyzed a set of DNC emails released by Guccifer 2.0 which consisted of 1,976 megabytes of data that were downloaded or copied over a period of 87 seconds on July 5 2016.
It's disappointing that even the Hackernews crowd, which is generally more skeptical and intelligent than the general population, has fallen victim to Russiagate hysterics. I get that Donald Trump is vile to many, but that's a sad excuse to let critical thinking go out the window.
