Your confidential files are not safe once uploaded online! The web is full of crawlers/spiders that are hungry for information and they will find your content – Trust me, even if you have not shared it to anyone.
Why dont you try it your self. Try searching Google with the search string below:
“not for public release” -.edu -.gov -.mil
Most confidential documents are appropriately labeled as “not for public release”, so searching google for such strings will yield to some interesting results. Same goes for the terms confidential, Top Secret, Clandestine, and so on.
So how do you prevent spiders/crawlers form indexing these files?
Well there are two ways of instructing crawlers to skip your content.
Feel free to search the web for more info on these techniques. Good luck! If you have something to add feel free to leave a comment below.