@Lash,
A not peer reviewed paper that when you delve into it states that less than 600,000 votes were stolen from Sanders.
Considering Clinton has almost 4,000,000 more votes than Sanders had and that 600,000 is less than 3% of the total vote, I don't see much there other than some eggheads trying to build a mountain out of nothing.
By the way, a poll usually has a margin of error of 3-5%. If Sanders lost 600,000 votes that is within the 3% margin of error.