Since 2009, health information for 12 million people has been improperly accessed through 178 significant breaches in California such as hacking, theft or loss. The U.S. Department of Health and Human Services tracks breaches affecting 500 or more people.
The chart above shows the sources of the California breaches. The most broad-reaching type of breach involves network servers, involving the information of about 9 million people. Paper or films were involved in the largest number of breaches. (Note that many breaches involved more than one source; those cases are counted in each category.)