this user.js is a suppliment that is intended to be appended to the ghacksuserjs user.js file which is a security and privacy centric user.js file for Firefox and its derivatives
you should probably read the relevent section(s) of the 'Firefox Configuration Guide for Privacy Freaks and Performance Buffs' before incorporating this user.js file, which depends heavily upon the properly configured uBlock Origin and uMatrix browser extensions or, at the very least, you should probably back-up your entire Firefox profile before importing the settings in this user.js
these preferences are my personal preferences - if you wish to modify anything, you might want to follow the advise contained in this user.js file in order to make updating your user.js easier