I have installed Raspbian on the Raspberry Pi. Due to the security policy in the company, we would like to block access to USB mass storage (pendrives, usb drives, etc.). I tried according to this article: https://www.raspberrypi.org/forums/viewtopic.php?f=91&t=91677 with the option:
chattr +i ~/.config/pcmanfm/LXDE/pcmanfm.conf
however, each entry in the file explorer options and change mount parameters makes it easily possible to use the storage. Is there any way to permanently block the ability to mount removable media?