I was aware of it but I think I was aware of it abstractly, theoretically. You know I understood who Edward Snowden was and what he did but I didn't really see the relevance that it bore in my life and doing film changed that tune pretty quick.

The razor-sharp line of division that exists between political ideologies in our own country in the United States, I think it's clear that these movements are forming - and one is more forward thinking and more embracing and more inclusive. The other is less tolerant and more judgemental and more fear-driven and fear-based. I think, you know, over the next generation, we're going to see which way we turn as a civilisation.

Zoe Saldana is such an angel. She’s got such an openness and vulnerability on camera and yet such great strength. She can kick ass with the best of them, but then she can soften and open up in a way that is magnetizing whether you’re watching her on set or on screen – she’s got a real power to her. I love her; we’ve known each other for years and it’s great to come back to that kind of familiarity, especially when you’re working with such intimacy.

I saw how vulnerable we all are and how exposed we all are and how this is an issue that affects everyone who owns a piece of technology. Which is certainly most people in this country.

People always ask me what I think, if Edward Snoden is a hero, if he's a villain. I don't really tend to moralize it so much as I feel like he's a whistleblower. He's someone who saw a wrongdoing and in order to shine a light on that wrongdoing had to bend some rules and break some laws along the way.

If it was a biopic about Glenn Greenwald, I would have immersed myself more fully in his personal life and gotten to know him as much as I could, but because it was much more about his relationship to this particular situation, to The Guardian, to Laura Poitras, and to Ewen MacAskill, and Edward Snowden, I was able to really learn a lot about him from reading his book and reading his many articles and accounts of that time.

We did monologues and scenes, and New York I did a scene from Amadeus and a monologue from Pounding Nails in the Floor With My Forehead by Eric Bogosian, and then in L.A. I switched the scene to This is Our Youth and did the same monologue. I was spiky-haired, super skinny. A lot of people were like, "You should come here and do a sitcom." That was the feedback that I got. Obviously it was quite a different journey than the one I've actually had, but I just listened to people.