Any time I hear someone use the phrase "social justice", I cringe. Nearly every person who uses that phrase has in mind some redistribution of society's wealth from those who are better off to those who are worse off. For them, "social justice" means "more nearly equal, ex post — after the fact; it means equality of outcome.
Justice should mean something different. Justice should mean equal treatment and equal opportunity. Justice should be an ex ante concept, not an ex post concept. It should have nothing to do with equality of outcome.
I once a attended a conference contrasting the views of Hayek and Pope Leo IX on social justice. In the end it seemed to me the primary difference was that the pope thought there should be a very high social safety net; Hayek argued that a higher social safety net meant there would be some serious disincentives for productivity. The higher social safety net might make the poor better off today, but it means there will be far more poor people in the future.
I'm not anti-redistribution. However, I tense up whenever I hear the phrase "social justice" because it is usually being uttered by some elitist interventionist eagre to create more bureaucracy and control more of our lives. Most people who preach "social justice" have no concept of programme assessment and programme evaluation to try to determine the effectiveness of their pet projects. And they rarely are willing to listen to economists and to examine the incentive effects of redistribution schemes.