Can't mount USB : "Not Authorized"

I think this could be the answer here:

https://help.ubuntu.com/community/Mount/USB

It says: "If your usb device doesn't appear on your desktop, you should check that your user has the correct privileges. Go to System->Administration->User and Groups, choose the user, click on "Properties", then go to the "User Privileges" tab. You should have the "Access external storage devices automatically" option checked."

In terminal, type:

sudo fdisk -l

The command output will show different devices; among them, you will find the one you want to mount. For instance, if it is /dev/sdb1, of type ntfs, you will want to type:

sudo mount -t ntfs /dev/sdb1 /media/your-username/ext-drive-folder/

Where the folder /media/your-username/ext-drive-folder/ is a folder you created for the external drive to be mounted in.

This would be annoying to do every time you want to mount an external device, but, "in case of emergency", it can be useful.

In gentoo, I had to edit the polkit rule /usr/share/polkit-1/actions/org.freedesktop.udisks2.policy and change the rule change allow_any rule to: yes