Twitter CEO Dick Costolo speaks during a discussion on social media with Brookings Senior Fellow Jonathan Rauch, right, on June 26, 2013 at the Brookings Institution in Washington, D.C. (MANDEL NGAN/AFP/GETTY IMAGES)

Twitter chief executive Dick Costolo said Wednesday that he’s not that worried about Facebook’s new foray into video via its Instagram service. The video feature, unveiled last week, directly competes with Twitter’s own Vine.

“People can do whatever they want to do,” Costolo said during a question-and-answer session at the Brookings Institution in Washington. Twitter, he said, is focused on that goal more than it’s worried about other companies taking its lunch.

The social network has a “very specific vision of where we want to go” with Vine, Costolo said, which is to make it easy to produce public, widely distributed videos.

“Other people can replicate that or take pieces of it if that’s what they want to do,” Costolo said. “If we do what we want to do, and go where we want to go, we don’t have to worry about what that guy’s doing over there.”

Along with taking questions, Costolo was at Brookings to talk about Twitter’s role in facilitating and participating in global political, news, entertainment and other discussions.

The executive said that he sees Twitter as the “global town square” and would like to make it possible for people in every country to access the network.

When a questioner asked Costolo, about how Twitter and other tech companies should handle data requests from the government — an issue under new scrutiny given the revelations about the National Security Agency’s PRISM surveillance program , the CEO gave a brief but careful answer.

“We’re going to principled,” Costolo said, but added that the service will also abide by the specific rule of law in the countries where Twitter operates.

On the lighter side, Costolo said that he likes how the network makes it easy for users to access the views of experts and other notable or high-profile people, highlighting Salman Rushdie as a prime example of a good Twitter celeb.

Costolo shared one example, which called his favorite Twitter moment, that he once noticed on the network.

Comedian Sarah Silverman had advised people annoyed with their families during the holidays to just close their eyes and “pretend it’s dialogue in a Woody Allen movie,” Costolo said.

Silverman then got a response from Allen’s former partner and a Twitter favorite, Mia Farrow.

Farrow’s tweet: “Tried that. Didn’t work.”

(Washington Post Co. chairman and chief executive Don Graham is a member of Facebook’s board of directors.)

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