Let's see...

TJ Max, UBS, Knight Capital, Heartland Payment Systems, Visa, Sony (already mentioned, but it's my fave), Stanford, Countless other hospitals, e-commerce vendors, banks, and other organizations that handle payment or personal information.

If you want to say "name a startup that's gone out of business because of a security problem" I'll let you away with that. There's still instances, and I'd love startups to pay more attention to security, but I know reality as well...