Is it possible within a Google Drive domain to have a shared folder with read/write permissions but not delete permissions that would copy a file that is "shared" with that folder instead of it being an alias of the owners file?
If not, is there something in the Google Drive API that would allow for a PHP script that would activate once something is "shared" in a "shared folder" that would authenticate as a different user and copy a file from the shared folder to a private folder?