Students at Columbia University staged protests to demand that the university divest (pull their investments out) from South Africa, to ensure they weren’t inadvertently sponsoring state-sanctioned racism during apartheid (legal racial segregation and discrimination in all areas of life). Specifically, they wanted the administration to divest stock it owned in American companies invested in South Africa, worth over $39 million. They used various strategies to get the administration’s attention, such as occupying buildings and chaining themselves to the walls. Eventually, the university sold the stock it held in companies doing business with South Africa, amounting to 4% of the school’s portfolio. The sit-in model has also been used by students elsewhere to advocate for other causes they supported, such as divestment from fossil fuels and other industries linked with social or environmental concerns. Read about it here and here.