Snowden’s first tweet asks, “Can you hear me now?”

Former National Security Agency contractor, Edward Snowden, joined social networking site Twitter on Tuesday and asked, “Can you hear me now?”

“I used to work for the government. Now I work for the public. Director at @FreedomofPress,” wrote the former NSA employee in the description of the account with the handle @Snowden.

Snowden serves on the board of directors of the nonprofit Freedom of the Press Foundation that is “dedicated to helping support and defend publicinterest journalism focused on exposing mismanagement, corruption, and lawbreaking in government,” according to its website.

“Can you hear me now?” wrote Snowden, who is currently living in exile in Russia, in his first post that was retweeted by 70,000 people.

Snowden, whose account was verified by Twitter, had 200,000 followers an hour after posting his first tweet, and 630,000 after six hours.

Astrophysicist Neil deGrasse Tyson was among the first to welcome Snowden to Twitter, “Feeling a Geek vibe. Edward @Snowden, the man behind the global mass surveillance revelations. Welcome to @twitter.”

Snowden was quick to acknowledge the welcome in his next tweet, “.@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.”

In the exchange of messages that followed, Snowden described himself as “a citizen with a voice” and neither a hero nor a traitor as his followers or detractors label him.

The astrophysicist, who hosts a radio show titled “Star Talk,” had urged Snowden to create a Twitter account during an interview.

“Meanwhile, a thousand people at Fort Meade just opened Twitter,” was Snowden’s last tweet of the day referring to the U.S. Army base in Maryland and home to NSA.

The only other Twitter account Snowden is following so far is that of NSA (@NSAGov), although the U.S. agency has not followed him back yet.