It took an outside security firm and days of analysis before Sony learned that user data was stolen, a Sony Computer Entertainment America rep recently told Kotaku. Sony said it originally learned that hackers breached the PlayStation Network on Tuesday, April 19, but it wasn’t until Monday that it discovered user data was stolen.
"There’s a difference in timing between when we identified there was an intrusion and when we learned of consumers’ data being compromised," Patrick Seybold, senior director of corporate communications for SCEA, told Kotaku. "We learned there was an intrusion April 19th and subsequently shut the services down.”
Sony then asked for assistance from outside experts, Seybold said, and “It was necessary to conduct several days of forensic analysis, and it took our experts until yesterday to understand the scope of the breach.”
This means, as far as Sony is publicly stating, the company did not know about the extent of the risk presented by the hackers until Monday, keeping them guessing for nearly a week. Earlier today Sony publicly revealed that hackers gained access to PSN user accounts. The company does not believe credit card information was taken, but it still warned of possible scams as basic user account information was likely taken.