Possibility of a folder audit software accessing your private files?
Private folders are only visible to one user only (YOU). They can't be accessed by any user. Also, if you're connected through a network, they can't access it either.
Based on my experience, I haven't heard of something that can intrude on a private folder.
But some of my friends (and me :D) are using decrypting/sniffing software to gain access on other's networks.
All I can say is that, any file/system can be access by any user, by any means necessary.
Try creating a VPN, it can lessen the chances of being infiltrated.
Try out this tutorial:
I Hope I helped you.