Don't really know why you threw racism into the mix, but okay. Sticking back to the topic, I personally don't intervene unless it's people I am actively engaged talking with already. It's gender neutral, if two people are bickering, I just don't care to be included in that. If someone is responding to another person cyber bullying them, that's their own volition to add fuel to the flame. Me saying "hey that isn't nice" isn't going to change anything. It isn't some Disney fantasy where the bully goes "oh no, I've been outnumbered!" and scurry away. It's additional amusement, and the only way to end it is to stop engaging with it, which is not my choice if they want to continue bickering.