So the list of all of the mods I did are as follows: 1. Modify /lib/udev/rules.d/50-udev-default.rules to comment out the line with MODE="0664" and make it MODE="0666" for the libusb section. This suppresses the messages that looked like this when I ran xsane: libusb couldn't open USB device /dev/bus/usb/001/001: Permission denied. libusb requires write access to USB device nodes. So make the mod below to fix that. # libusb device nodes #SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0664" SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0666" 2. Made my user a member of the lp group. Even with the fix in step 1, the permissions on the scanner port always were still set to 664. The ownership of the /dev/bus/usb/002/002 object was root.lp so adding myself to the lp group resolved the last of the "libusb couldn't open usb device" messages.