One way that's worked for me in the past is to give in slightly to the person's demands (even by just conceding their point in an argument), and observe how they react. If this cools their rage, then they are expressing sincere pain due to a wrong that has been done to them, and only desire justice in some form. This person has legitimate concerns and deserves support.
If getting their demands met enrages them even more, then by listening to them you are only feeding a fire in their heart that will consume everything if allowed to. You have to stay away from those people.
Emotions cause some noise in this process so you shouldn't rush to judgment.
I call this the difference between "Social Justice Warriors" (shameful that this has become a negative term because being a warrior for social justice describes every great leader) and "Social Grudge Warriors".
Most narcissists thrive on social validation. Virtue signaling is almost always a narcissistic trait. Just observing people or having a conversation with them that involves solving a problem, but not necessarily their way, straight up outs narcissists and their tendencies.
There is another complication here though. I remember from my years as a political activist in college, those years can be quite angry, about everything. It's very easy to fall into the outrage trap, and there's also peer pressure to do so if your other friends are involved.
It's something that _most_ people grow out of and mature and realize that not every slight is intentional and demands wrath and justice. To be clear, I'm not saying they don't have a point, but that sometimes their messaging is very, very aggressive.
My rule of thumb follows yours, but I also make allowances for young people striving to make their mark in ways their peers tell them they should.
One way that's worked for me in the past is to give in slightly to the person's demands (even by just conceding their point in an argument), and observe how they react. If this cools their rage, then they are expressing sincere pain due to a wrong that has been done to them, and only desire justice in some form. This person has legitimate concerns and deserves support.
If getting their demands met enrages them even more, then by listening to them you are only feeding a fire in their heart that will consume everything if allowed to. You have to stay away from those people.
Emotions cause some noise in this process so you shouldn't rush to judgment.
I call this the difference between "Social Justice Warriors" (shameful that this has become a negative term because being a warrior for social justice describes every great leader) and "Social Grudge Warriors".