Revoking shared file access can be challenging because permissions are often persistent copies or tied to specific versions. When you share a file link (like "anyone with the link"), granting access creates a unique entry point. Subsequent attempts to restrict that specific link might be ineffective if recipients already accessed it and downloaded a copy or accessed cached versions. Unlike recalling an email, file systems don't allow actively pulling back copies once distributed; you control the original file's future access, not any existing copies that have already been acquired by recipients.

Common scenarios include sharing cloud storage links via platforms like Google Drive or SharePoint. If you grant a collaborator "Viewer" access to a document and they download it to their device, revoking the original share link stops future access via that link but doesn't delete their saved copy. Similarly, internal network file shares might allow users to open files while connected; offline caching or saving a local copy persists even if you later remove their permissions on the central server.

The main limitation is loss of direct control over disseminated copies, posing privacy/data governance risks. While updating access policies affects future openings of the original file, it rarely retroactively removes content already accessed. This necessitates careful sharing practices (like using expiration dates where possible and limiting initial permissions) and highlights the importance of legal agreements governing shared sensitive data. Future systems aim for better "unsharing" mechanics, but technical constraints of data replication persist.