As noted on our blog, many users turn social media into a platform for perpetual outage, with their outrage volume set to 11. Why do they do it?
A research paper explains:

Getting outraged on others’ behalf often isn’t about altruism but soothing personal guilt and asserting one’s status as a good person.

Source: Moral Outrage Is Self-Serving, Say Psychologists
In other words, the perpetually outraged think they are virtue signaling that they are better than others.
And

“When people publicly rage about perceived injustices that don’t affect them personally, we tend to assume this expression is rooted in altruism—a “disinterested and selfless concern for the well-being of others.” But new research suggests that professing such third-party concern—what social scientists refer to as “moral outrage”—is often a function of self-interest, wielded to assuage feelings of personal culpability for societal harms or reinforce (to the self and others) one’s own status as a Very Good Person.”

Very, very, very few outraged posts I see on social media have to do with issues that impact the outraged poster, directly. This is why I have been perplexed by the level of outrage displayed. The study described here, however, finds that directing “outrage at a third-party decreased guilt”. Expressing outrage “inflated participants perception of personal morality” – in other words, social media outrage is virtual signaling that you are better than others.