WASHINGTON, UNITED STATES (Reuters) - Edward Snowden has come in from the cold - on Twitter.
Snowden, a former National Security Agency (NSA) contractor who leaked details about the US government's massive surveillance programs, started a Twitter account on Tuesday from exile in Russia with a simple handle - @snowden.
He attracted more than 171,000 followers in about an hour and had 548,000 about 4-1/2 hours later. But Snowden was following only one other Twitter account: his former employer's.
"Meanwhile, a thousand people at Fort Meade just opened Twitter," Snowden said in a tweet, referring to the US Army base in Maryland that is the home of the NSA.
Snowden's initial tweet had been "Can you hear me now?" The message, a take-off on a cellphone provider television commercial, was retweeted 25,000 times within an hour. In his Twitter profile, Snowden described himself by saying, "I used to work for the government. Now I work for the public."
Supporters see Snowden as a whistleblower who boldly exposed government excess but the US government has filed espionage charges against him for leaking intelligence information. Snowden left the United States in May 2013 and has been living in Russia since being granted asylum there later that year.
In his earlier hours on Twitter, Snowden exchanged tweets with prominent astrophysicist and radio talk show host Neil deGrasse Tyson, who had encouraged Snowden to try Twitter during an interview on his show this month.
On Twitter, the two discussed the discovery of water on Mars and Snowden joked that his work for the Freedom of the Press Foundation keeps him busy, "but I still find time for cat pictures."
Tyson asked how he felt about being considered a traitor as well a hero, noting that "you're a geek to me." Snowden responded that he was "just a citizen with a voice."
The user name @Snowden had already been claimed by someone who had not used it in three years. The American Civil Liberties Union, which represents Snowden, said Twitter officials were contacted and agreed to turn over the handle to Snowden.
U.S. President Barack Obama started his own Twitter account, @POTUS, in June and reportedly had more than 1.6 million followers in less than 24 hours.