Florida had charged the Tampa resident as an adult with 30 felonies. In August, Clark pled not guilty.
As a child, Clark found ways to trick players of the video game Minecraft, people who knew him at the time told The New York Times.
He moved on to selling and swapping rare social media usernames on the forum OGUsers, where he connected with other hackers who said they participated in the Twitter breach, according to the newspaper.
A report released in October by New York's Department of Financial Services said that Twitter suffered from cybersecurity shortfalls that enabled the “simple” hack attributed to the Florida teenager to take over the accounts of some of the world's most famous people.