One interesting feature I remember from Truecrypt was the ability to crash the system (using a user defined custom key) in an emergency shutdown to protect encrypted host data from seizure.
On Linux the way this would work is to enable the kernel feature for it and have a script execute the sysrq-trigger on demand - mapped to a key of the user's choice.
Then type the following commands at a shell prompt:
echo 1 > /proc/sys/kernel/sysrq
echo c > /proc/sysrq-trigger