I ran
chown -R me:me /opt/web/ftp-mounts/
which affected files on sshfs ftp mounts. The remote server hosts IIS based websites. I might have messed up the file permissions on the remote host.
Now when I request static files on my production website, I get IIS error
HTTP Error 404.9 - Not Found
This error occurs when the requested file is marked as hidden on the file system.
How do I revert these? I just messed up my production server!