I would like to copy files between Galaxy S3 and Ubuntu
without giving away too many privileges - just copying said file
without any rooty system modifications (I want to keep the carrier-warranty including their system updates - currently 4.1.2; and I want to show this to hapless users too - without them calling me back...)
without using an USB cable (I know how to do this like in this answer, that is, connecting as a camera ; but this gives one complete rw access in some directories)
preferably without any extra apps to install.
It seems there are two options left (when going through the list offered by the "Share via" button): either Bluetooth or Wi-Fi.
When I try to send it via Bluetooth I just get the notification: "Bluetooth share: Sent 0 successful, 1 failed". However, I can transfer files from Ubuntu to Android.
So how can I copy files successfully?