Even if you’re not that active on social media, you’ve probably experienced it: the sudden wave of dread that overwhelms you when you realize you’ve said something you shouldn’t have – and someone has noticed.

You’ve been called out: your mistake suddenly feels grave and irreparable; you may even worry that this one episode could affect your whole life.

A version of call-out culture has been functioning for centuries as a tool for the marginalized and their allies to reveal injustice and the need for reform. The practise of directly addressing inequality underpins countless social justice movements, from civil rights to Standing Rock.

The contemporary idea of a “call-out”, however, generally refers to interpersonal confrontations occurring between individuals on social media. In theory, call-outs should be very simple – someone does something wrong, people tell them, and they avoid doing it again in the future. Yet you only need to spend a short amount of time on the internet to know that call-out culture is in fact extremely divisive.

Former president Obama pointed out this week at the Obama Foundation Summit in Chicago that call-outs can give the illusion that you’re effecting change, even if that is not true. “If I tweet or hashtag about how you didn’t do something right, or used the wrong word or verb, then I can sit back and feel pretty good about myself, because, ‘Man, you see how woke I was. I called you out.’ That’s not activism,” Obama said.

A reason call-outs can be polarizing is they often challenge the status quo. They can spark discomfort and offense, as when Canadian activist Nora Loreto went on Twitter to suggest that the C$15.2m raised to support the Humboldt Broncos junior ice hockey team after a deadly bus crash last year was donated so generously in part because victims of the accident were young, male and white. Or earlier this month when, in response to Ellen DeGeneres tweeting about her friendship with George W Bush and kumbaya policy of being nice to everyone, critics pointed out that niceness is not an unalloyed good.