The Easter Seal Society of Superior California is first sending out notification letters concerning a laptop stolen on December 10. From their notification letter:
On December 10, 2013, an Easter Seal Society of Superior California (“Easter Seals”) employee’s vehicle was broken into and a number of items, including a work-issued laptop computer, were stolen. Upon learning of this incident on December 10, 2013, Easter Seals immediately launched an internal investigation, hired specialized data security counsel to assist in the response to this incident, and retained external forensics experts to assist in determining the scope of this event.
These investigations revealed that although the computer was powered off, password protected, and not connected to the internet at the time of theft, emails containing the health information of certain Easter Seals clients and potential clients could still be accessed.
While we are unaware of any actual or attempted fraud pertaining to your child’s health information, we nonetheless wanted to notify you of this situation so that you may take steps to monitor your child’s identity should you feel it is appropriate to do so.
Although these investigations are ongoing, it has been confirmed that these emails contained your child’s name, date of birth, health care provider information, health care billing information, patient identification number and occupational therapy notes.
You can read the full letter here (pdf).
Update: The Sacramento Bee reports that 3,026 were affected.