If you use Dropbox, you should change your password according to an email the company sent to some of its users.
The email provides little information about the reasons that led the company to warn its users, and appears to be a reaction to a security incident that took place in mid-2012.
We are contacting you to inform you that if you have not updated your Dropbox password since mid-2012, you will be prompted to update it the next time you log in. This is purely a precautionary measure, and we apologize for the inconvenience.
To learn more about why we take these precautions, please visit our Help Center page. If you have any questions, please feel free to contact us at password-reset-help@dropbox.com.
The email sent by Dropbox contains a link to a FAQ help page that answers some of the questions.
It appears that Dropbox has discovered a leak that includes a list of Dropbox account names (usually an email address), and salted passwords.
So not all Dropbox users will receive an email to change their password, only the email addresses that the company believes have been leaked.
Of course, it would be a good idea if you use the service to change your password, regardless of whether you receive an email from the company.
