Shared files can be downloaded and copied by everyone allowed to read them. So they can end op on any backup, hard disk, USB stick, web storage or website, in short whereever the receiver wants to store or publish them. Since you can't touch those files there, you can't recall them either.
You can make this somewhat more difficult by using restrictions built into pdf (such as don't copy), or presenting your document as html with browser restrictions. Then people would have to make screenprints to copy the content for others or for later use by themselves.
Anyone knows of a solution where I can share my contracts and proposals via Gdrive, Skydrive etc. but make sure that I can expire or recall the files when no longer needed? I don't want my files to be misused.
You must surely be aware of the cloud security issues arising and I feel uncomfortable sharing my confidential docs with partners via dropbox. Please share your views too on how you protect your files. This would certainly help me. Please comment.