(CBS SF) — In less than six hours of creating a Twitter account, former National Security Agency contractor Edward Snowden amassed over 640,000 followers — six times more than the NSA’s account.

Snowden’s first tweet “Do you hear me now?” was a subtle jab at government officials who labeled him as a traitor after he leaked classified information about numerous U.S. surveillance programs around the world.

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But perhaps the more symbolic gesture is the sole Twitter account he chose to follow: the NSA.

Twitter, which verified Snowden’s account with a blue check mark, published a GIF showing how many people across the world began to follow him since Tuesday morning.

Astrophysicist Neil deGrasse Tyson engaged Snowden in his first Twitter conversation, starting with a welcome.

Snowden responded, “@neiltyson Thanks for the welcome. And now we’ve got water on Mars! Do you think they check passports at the border? Asking for a friend.”

Tyson asked if he was staying busy.

“Surveillance never sleeps, and secret projects @FreedomofPress are keeping me busy,” Snowden said, “but I still find time for cat pictures.”

Then Tyson asked what he thought of the labels “hero” and “traitor.”

“Hero, traitor — I’m just a citizen with a voice,” Snowden said. “@DanielEllsberg told me #labels never stopped progress. Neither in 1776 nor today.”

Tyson tweeted back at Snowden “you’re a patriot to me. Stay safe.”

Nicole Jones is a digital producer for CBS San Francisco. Follow her musings @nicjonestweets

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