Hey guys, just heads up to change your passwords!, here is the story on the hacker news Link

Actually Dropbox not hacked, and the majority of the logins posted so far either are not related to Dropbox or are from inactive accounts. Looks like yet another case of someone posting a database of stolen credentials that were being reused by people across sites and services, and the 'hacker' was trying all the major players to see if anything hit. Dropbox states it had already reset passwords on all accounts it had identitied at being at potential risk from this particular non-exploit.