media-libs/libmtp (-1.0.1, also older versions) installs /etc/udev/rules.d/65-mtp.rules. This files gives "666"-Permissions to all detected mediaplayers. Reproducible: Always Steps to Reproduce: Plug in a mediaplayer. Check permissions on device node. Actual Results: # ls -la /dev/bus/usb/001/014 crw-rw-rw- 1 root plugdev 189, 13 Oct 12 17:48 /dev/bus/usb/001/014 Expected Results: drop world read/write rights. Maybe change group to "audio" instead of "plugdev"? a simple s/666/660/ on the rules-file should do the trick...
fixed in libmtp-1.0.2-r1