Yes, it is stupid to leave your computer unlocked but it happens all the time in every workplace. If spending a minute pulling two files from an unlocked system

Yes, it is stupid to leave your computer unlocked but it happens all the time in every workplace. If spending a minute pulling two files from an unlocked system is all it takes to get access to all of person's passwords - that's scary. And this would be trivial to mitigate, NSS already has everything necessary. Note that full disk encryption offers exactly no protection if you forgot to lock your computer. Not that full disk encryption is common, almost nobody does that.