Largely we excluded these people from conversation with social cues and sold them back their prejudices via red-top newspapers, which mostly kept their brain farts and prejudices suppressed.
For better or worse, you can't do that with the internet. Facebook and twitter seem hell bent on not only encouraging their appalling behaviour but amplifying it.
The only way to stay away from them is to stay ahead of them and stay away from any medium these idiots think is "their place".