Sony executives are apologizing for last week's PlayStation security breach.

Over the weekend, they admitted that they still don't know who's to blame.

Personal data of 77 million people was compromised. In an effort to make it up to their customers, Sony will be offering 30 days of free service.

 The PlayStation breach is just the latest hack attack on a company's customer data, but online customers are still entering more private info than ever.

 Experts say that means there's little incentive for companies to improve their computer security.