The problem we face with eradicating this on social media is that for some people being labelled racist is not a bad thing.
In any setting be it Instagram, WhatsApp or whatever you get a bunch of kids posting monkey emojis simply because they're being little cnuts and know they're not supposed to do it. Not because they're racist. Tomorrow they'll be on somebody else's page doing something totally different. Focusing on that misses the point imo.
Hiding behind that you have the actual racists, inciting it, posting more serious stuff and messaging players directly. These are the ones that need to be stopped, but how? Like the old ASBOs if you prosecute these people its not a bad thing to them, half of them will see it as a badge of honour in their families and communities who bred those views in the first place. If anything, with the way world is going it will entrench them further in their views. How do you stop it when the parents and friends agree with it?