Removable devices are no longer user writable in Jessie
Originally created by @anonym on #8273 (Redmine)
In Wheezy, a plugged USB storage medium is writable by the floppy
group, which the Live user is a member of, so liveusb-creator can
install Tails to it. This ownership came from the
rule:
SUBSYSTEM=="block", SUBSYSTEMS=="usb|ieee1394|mmc|pcmcia", GROUP="floppy"
in /lib/udev/rules.d/91-permissions.rules
, but it’s absent in Jessie,
so the device is owned by group disk
, preventing the user from
modifying the USB storage, and, in particular, to install Tails to it.