I've honestly never heard of Gab but then again I stay away from social media completely (other than steam lol). I have seen a few on twitter posted by some 4chan members, it's definitely a thing. I have also noticed some people around me waking up to the nonsense they promote too. There isn't much you can do about it other than staying away from social media (because let's be honest, saying anything true will be banned). Tell those you love what you know if they ask or are curious, don't force it to them if they don't ask (they will never understand, trying to show my brother ww2 camp edits but still poor MuiJews). Like others said there is a warfare going on but I do believe it's best to avoid social media completely.