He's 24, unemployed and has no specialized computer skills. Using sheer wit and persistence, the Frenchman managed to infiltrate Twitter administrators' accounts and post confidential company documents online, a prosecutor said Thursday.
"Hacker Croll," as he was known online, also used the administrators' access to peep at the Twitter accounts of President Barack Obama and singers Britney Spears and Lily Allen, though he didn't have access to sensitive information about them, the prosecutor said.
The suspected hacker was held for questioning this week before being released Wednesday, police officials said. FBI agents sat in on the sessions, said Jean-Yves Coquillat, prosecutor in Clermont-Ferrand, where the suspect will be tried in June for hacking.
If convicted, he risks up to two years in prison and a euro30,000 ($40,068) fine. The suspect lives near Clermont-Ferrand in central France.
"He says it's the challenge, the game, that made him do it," Coquillat said. The prosecutor said preliminary investigations suggested Hacker Croll did not seek to profit from his Twitter activities or tweet in other peoples' names.
Coquillat said Hacker Croll confessed to the hacking under questioning, and analysis of his computer backs up his statements.
The suspect, who lives with his parents and has no college degree, didn't have any special computer training, the prosecutor said.
His technique was to get administrators' e-mail passwords' reset by correctly answering their security questions using information about his prey that he gathered from blogs and other public sites.
Twitter said in July that it was the victim of a security breach. Co-founder Biz Stone wrote at the time that the personal e-mail of an unnamed Twitter administrative employee was hacked, and through that the attacker got access to the employee's Google Apps account.
The French prosecutor said the suspect infiltrated the accounts of "several" Twitter administrative employees. He was able to access information such as contracts with partners and resumes from job applicants, Coquillat said.
Hacker Croll e-mailed some of the documents to TechCrunch, a widely read technology log, and it subsequently published some of them, including financial projections. The material was also published on several French sites.
Some of the material was more embarrassing than damaging, like floor plans for new office space and a pitch for a Twitter TV show.
Using the administrator logins, Hacker Croll looked at Twitter details of Obama, Allen, Spears and other well-known personalities and was able to see information such as IP addresses, when they were last connected and when they signed up.