FB has definitely made it easier; it's just a matter of a button click. (Share button)
And of course, the more you associate and interact with groups that fit your opinions and interests, the more Facebook and other ad-supported services will try to prioritize showing you those posts, so the echo chamber effect is amplified.
And when you step out into the real world, you'll be inclined to think of others that don't share your "informed" opinion as uninformed or naive, after all you have seen all this evidence to back you your opinions and theories. [Edit:spelling]
In general, in these situations, it seems that the greater tyrant always seems to win, to the detriment of the community.