Husam Sam Asi/YouTube Screenshot by Chris Matyszczyk/CNET

I have just received the video equivalent of a plain brown envelope slipped beneath my door.

It was a link to a YouTube video that hardly anyone appears to have seen.

On screen is Matt Damon, who appears to be talking to a journalist of foreign provenance.

He is being asked what he thinks of Edward Snowden. Astonishingly for someone who has been Jason Bourne and knows the danger of such things, he is answering the question.

"I haven't read everything that he's leaked," he admits. Who has? Even the government doesn't know what Snowden secreted on his gadgets.

He added that he thought Snowden seemed like a "conscientious guy."

You'd think Damon would know a good performance when he sees one. So, one assumes, he feels that Snowden is entirely without artifice.

He described the revelations as "pretty shocking."

And he declared: "On balance, I think that it's a great thing that he did."

He then proposed what seemed to be a vote on the whole contentious matter of surveillance and its implications for national security. It might make some think of European-style referendums.

"If we're going to trade our civil liberties for our security, then that should be a decision that we collectively make," he said.

Oh, but collectivism doesn't always work. The great movie "The Lives Of Others" rather proves the point. I wonder if Snowden can get a DVD of it in Russia.

Damon has rather fallen out of love with the current US government. He recently told BET of President Obama: "He broke up with me."

One hopes he at least did it in person. It's rude when people do it by text or Skype.

It is, though, a tempting and charming notion that we could all get together and decide on how much of our civil liberties we really ought to give up or not. We could even make it an annual event and vote through our Facebook accounts.

However, can we truly trust ourselves? We are, after all, the bright sparks who voted in the current Congress.