The landmark and rather opaque tweet was sent at 1544 GMT Saturday by GGGGGGo_Lets_Go, a Tokyo graphic designer for an advertising agency. It said: "So that means the barrage might come back later all at once."
Twitter took four years to reach its 10 billionth tweet, in March this year, and less than five months to double it. GGGGGGo_Lets_Go was inundated with congratulatory messages from around the world for hitting the milestone with a tweet which appeared to have been part of a longer conversation with another user.
He later posted another message, saying: "Looks like I posted the 20 billionth tweet. I'm getting replies from people all over the world. It's scary. What are the chances? Maybe I'm going to die."Is it more amazing than winning the lottery? I thought it was a joke."
Read more at - 'Twitter user sends world's 20 billionth tweet'