So many companies get hacked every year--the latest being the Sony one--that it's hard to keep track of which sites and services have had consumer data stolen. This chart from Information is Beautiful revels the biggest data breaches over the last few years and how hackers got that data.
The Adobe hack in September 2013, in which 152 million records containing user IDs, passwords, and credit card information, looks to be the biggest, followed by the Ebay leak in February and early March of 2013. Both were the work of hackers.
Other compromises on the chart were the result of accidentally published sensitive information, lost or stolen media or computers, inside jobs, and viruses.
The chart only shows data losses of over 30,000 records, and it's a telling look at our ongoing struggle with information security. You can see the interactive version of the chart at Information is Beautiful.