Tails Linux wipes active memory when the USB drive is removed

Tails Linux will automatically shut down and forcibly erase memory of the running operating system if the USB drive is removed while powered on:

Tails erases active memory by using a custom udev watch-dog binary:

amnesia@amnesia:/etc/udev/rules.d$ ps -ef | grep wat
root      5877     1  0 00:59 ?        00:00:00 /bin/sh /usr/local/lib/udev-watchdog-wrapper
root      5886  5877  0 00:59 ?        00:00:00 /usr/local/sbin/udev-watchdog /devices/pci0000:00/0000:00:14.0/usb2/2-1/2-1:1.0/host1/target1:0:0/1:0:0:0/block/sdb/sdb1 disk

Full details can be found here.