Joseph Gordon-Levitt put a plaster over his webcam to prevent government surveillance.

The 35-year-old Hollywood actor plays the role of Edward Snowden, the National Security Agency whistle-blower who is currently living in exile in Russia, and has admitted that his experience on set has made him more conscious of privacy issues.

Asked whether he has put a plaster over the camera on his computer, Joseph shared: ''I have done it. But the thing's fallen off and I need to find another one.

''It's funny: putting a Band-Aid or piece of tape over your webcam only scratches the surface of addressing the big question.

''I do think I've become more thoughtful about what this technology is. I tend to be really optimistic. I was raised to embrace technology. My dad always made sure we had a computer in our house.''

Joseph - who stars alongside Shailene Woodley and Zachary Quinto in the Oliver Stone-directed movie - admitted he cherishes his privacy.

He told the Metro newspaper: ''Alone time is important to me. Having my privacy, having my moments to explore and try things and say, 'What do I think?' and write in my journal and talk to myself ... this is how I feel about who I am, how I feel about things, about myself.

''And it would be very different to know someone was reading those journal entries or listening in on while I was having those private conversations. It's important to have a boundary.''

Despite this, Joseph admitted he has Googled his own name, because he's been curious to know what people think of him.

He said: ''I have done it. I try not to spend too much time doing that because it's really not productive.''