As part of the "We clean Serbia" campaign, the city government of Belgrade displaced 17 Romani slums that were on or near the dumps, which were formally classified as "unhygienic settlements". These informal settlements, where residents worked as waste pickers, were largely the direct result of the Yugoslav wars—especially the Kosovo war—as most of the residents came to inhabit these settlements as internally displaced persons (IDP's), refugees, or repatriated refugees. An estimated 75% of recycled materials in Serbia are gathered by informal waste pickers; however, this activity is illegal.