Edward Snowden, the former government contractor who leaked thousands of classified NSA documents, has officially joined Twitter.

"Can you hear me now?" Snowden tweeted at noon ET, 7 pm Moscow time.

Snowden's Twitter profile bears the blue check mark, meaning Twitter has verified that Snowden is the true owner of the account.

Snowden agreeing to join Twitter was particularly notable because of the warnings he has given about how much the government can learn about individuals from their private and online communications.

Snowden is following only one account - @NSAgov.

"I used to work for the government. Now I work for the public," Snowden's profile reads.

His occupation: Director at Freedom of the Press Foundation, a non-profit "dedicated to helping support and defend public-interest journalism focused on exposing mismanagement, corruption, and law-breaking in government."

Can you hear me now? — Edward Snowden (@Snowden) September 29, 2015

Snowden has lived in Russia, where he has been granted asylum, since leaking classified NSA documents to reporters in 2013.

In a second tweet, Snowden noted that water was discovered on Mars and wondered if they check passports at the border. "Asking for a friend," he joked.

.@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. — Edward Snowden (@Snowden) September 29, 2015

Within 45 minutes of his first tweet, Snowden amassed more than 110,000 followers, and Twitter co-founder Jack Dorsey had written a personal welcome: "Yes!" Dorsey tweeted. "Welcome to Twitter."

Snowden, a hero to some, a traitor to others, was hired by NSA contractor Booz Allen Hamilton in 2013. Shortly thereafter he leaked thousands of classified NSA documents to the journalists Glenn Greenwald, Laura Poitras and Evan MacAskill, which were published in The Guardian and The Washington Post.

Snowden fled to Hong Kong and then Moscow, where he stayed for one month before being granted asylum.