Moore, who announced plans Thursday to divorce Kutcher, took on the handle in jokey recogniton of her then-husband's intense involvement with the medium. Kutcher famously became the first person to reach 1 million Twitter followers in April 2009 after challenging CNN in a race to the landmark.
He celebrated his victory by promising to donate $100,000 to help prevent malaria.
Kutcher, who uses the handle @aplusk, has since reached more than 8.3 million followers. Moore, who kept her name has more than 4.2 million.
True to form, Kutcher took to Twitter again Thursday to respond to her decision to divorce him, following months of tabloid reports claiming infidelity on his part.
"I will forever cherish the time I spent with Demi," he tweeted. "Marriage is one of the most difficult things in the world and unfortunately sometimes they fail. Love and Light, AK."
There was no sign of Moore on Twitter after her divorce announcement Thursday afternoon, and her old handle remained as of Friday morning.
Kutcher took to Twitter frequently in the months before the divorce announcement to try to dispel speculation about his marriage. In late September, he tweeting a link to the music service Spotify to indicate that he was listening to Public Enemy's "Don't Believe the Hype." He later wrote, "When you ASSUMME to know that which you know nothing of you make an ASS out of U and ME."
At about the same time, Moore posted a photo of herself with her eyes closed and the caption, "I see through you…."
Fortunately for Moore, Twitter names are easily changed.