http://www.makeuseof.com/tag/recover-lost-files-dropbox/ - "But what
happens if you accidentally delete a file? Will it be gone forever
once the changes are synced to Dropbox? Yes, the file will disappear
from your Dropbox folder. However, it won’t be entirely gone just yet.
So is there a way to recover lost files from Dropbox after it was
deleted? This being the super smart Dropbox, there certainly is!..."