I set up a Ubuntu 14.04 machine for my family.
I noticed that when I insert a USB key it gets automounted to /media/$username/$volumename. /media/$username has an ACL that only allows $username to access the medium, causing problems when switching users. The new user has no rights whatsoever, so the only options are pulling out the USB key and re-inserting it.
Googling, I found this: https://askubuntu.com/a/276670. Using this udev rule I managed to tell udisks2 to automount media to /media/$volumename. Still /media/$volumename has permissions set to 700, causing the same problems.
I suspect that udisks2 uses a restrictive umask for automounts. Does anyone know how to change the umask? Is there a possibility to set the group of the mount directory (so that I could use 770 permissions)?
/etc/fstab is not a solution, since this has to work for automounts of unknown media.