When I share a file and allow others to share the file on, they can share that file with any number of personal folders and communities that I don't have access to.
If I remove the ability for others to share my file later on. Those shares are not removed so through that the file could still easily be shared with more people as adding anyone to the folder or community will automatically give them access to the community.
This is not so much a problem for communites and folders I have access to as I see them listed in the Sharing tab, can individually remove them and can access them to check membership but for shared folders and communities with whom the file was shared to which I don't have access it is a potential problem as I have no control over which these are and who has access to them. I don't see these mentioned on the sharing tab and only see a grey message stating "This file is in X folders or communities you do not have access to".
The only option I have to remove these is to use the "Stop Sharing" button but this will also remove all known people, folders and communities which I might want to keep. Ideally I would want to be prompted as an owner when I set the option to "not allow people to share my file" to also remove the file from any folder, or community I don't have access to. Currently I'm not even warned about these folders & communities and it could cause unwanted data leaks. Plus it makes it very unclear to users as to who has access to their files.
We just tested this on C7 and if you click the "Stop Share" button it will indeed remove it from all shares, including the ones where someone else shared the file with a private Community that the owner did not have access to.
The Warning message was also clear in describing what is about to happen. I hope this resolves this ER.