"We do know that the information was accessed," Sony Computer Entertainment boss Kaz Hirai said in an recent BBC interview. "We don't know what part of the accounts were taken from our servers." The hackers might have stolen first names or just the last four digits of telephone numbers.
"It could be the entire account information," Hirai added. "We just don't know."
That's not all Sony doesn't know. Hirai said that the intruders were "very good" at covering their tracks on their way out of Sony's servers.