Greenwald, 62, began his career in television before directing movies, including the kitsch classic Xanadu, starring Olivia Newton-John. The death of his father and the 9/11 attacks convinced him to switch to doing more socially worthwhile work. He began making feature-length documentaries, tackling such targets as Fox News - in 2004's Outfoxed: Rupert Murdoch's War on Journalism - and the world's biggest retailer in Wal-Mart: The High Cost of Low Price.

The films were critically praised and reached a large audience, but Greenwald decided to abandon long documentaries and move into producing fast turnaround online videos 16 months ago.

Calling it "an interesting transition", Greenwald recalls being in the same editing room a few months ago in which he once edited a six-hour mini-series. "Back then I was trying to lose 20 minutes from an edit - now the finished film I am making may only be four minutes long and the job is to lose 20 seconds."...

"You could spend 12 months making a documentary and releasing it, and having your moment in the sun about something that may no longer be in the news cycle any more. Or you can spend 24 hours to put together a short viral video which can actually make a difference." 

We interviewed Robert at plugincinema, as well as flagging Outfoxed as an interesting example of open source media . How is he funded, you might ask? 8,000 subscribers who give monthly donations of around $10 a month.