"For that reason we felt that it was important to publicize this attack while we still gather information, and we are helping government and federal law enforcement in their effort to find and prosecute these attackers to make the Internet safer for all users."
The hack is the latest high-profile cyber-attack on US media and technology companies recently. The New York Times and The Wall Street Journal reported this week that their computer systems had been infiltrated by China-based hackers.
One expert said that the Twitter hack probably happened after an employee's home or work computer was compromised through a vulnerability in Java, a commonly-used computing language whose weaknesses have been well publicized.
