This is from Mother Jones Magazine in an article entitled Tehran in Turmoil posted today, June 22, co-authored by Nick Baumann, James Ridgeway, and David Corn, well-known investigative reporters:
There are also clandestine videos being released on YouTube and elsewhere, most of them shot on cell phones, showing the beating, tear gassing, and shooting of protestors. This one, sent to us by an Iranian reporter, reportedly shows how the Ahmadinejad regime prepared stacks of fradulent ballots before the election even began. (source)