Here's Why Dropbox Has Been Opening Your Private Documents
When you post certain types of private documents to Dropbox and tell Dropbox to share them with no one, Dropbox itself will still open them up and take a look.
It does this in order to make a "preview" version of the document, the company says.
The fact that Dropbox is opening documents came to light when security expert Daniel McCauley, who writes for WNC InfoSec Blog, was playing with a new service called HoneyDocs. It tags a document and then privately tells you every time someone opens it.
McCauley wanted to see if cloud storage documents were being viewed in ways he didn't know about. So he uploaded a bunch of files to his Dropbox account.
Lo and behold, Honeydocs told him that all of the documents with a ".doc" extension had been opened.