Summary Box: Hospital breach puts data online

WHAT HAPPENED: A privacy breach led to the posting online of medical information for thousands of emergency room patients at Stanford Hospital in California.

HOW IT HAPPENED: Stanford Hospital is blaming a subcontractor used by an outside vendor. It says a file that contained the patient information was posted to a website. It says the vendor is investigating.

THE CONTEXT: Breaches of medical data are common though most typically involve lost or stolen computers or storage devices. Roughly one-fifth of the publicly disclosed breaches in the last seven years have involved health care providers, according to the Privacy Rights Clearinghouse.