Apparently, on reddit, a bunch of dropbox user information was leaked and Dropbox was claimed to be hacked. Dropbox denies the rumors, but they seemed to have forced a password reset for the affected users anyway. They say this leaked information was from third-party sites and was old information. If you're a dropbox user, you should change your password just to be safe.
Ironic since Edward Snowden, former NSA employee, said to get rid of Dropbox, Facebook, and Google if you care about your privacy - and not too long ago.