http://www.zdnet.com/dropbox-gets-hacked-again-7000001928/
Dropbox gets hacked ... again
Summary: After last year's embarrassing data breaches, Dropbox promised to implement additional safeguards "to prevent this from happening again." Whoops, it just happened again.
Running a secure online service is hard work. It costs money and it requires nonstop vigilance.
It’s the kind of work that gets tested regularly. How a company responds to security challenges defines the difference between earnest startups and companies that deserve to graduate to the big time.
Dropbox just failed that test.
Our investigation found that usernames and passwords recently stolen from other websites were used to sign in to a small number of Dropbox accounts. We’ve contacted these users and have helped them protect their accounts.
A stolen password was also used to access an employee Dropbox account containing a project document with user email addresses. We believe this improper access is what led to the spam.