A waste picker is a person who salvages reusable or recyclable materials thrown away by others to sell or for personal consumption. There are millions of waste pickers worldwide, predominantly in developing countries, but increasingly in post-industrial countries as well. Various forms of waste picking have been practiced since antiquity, but modern traditions of waste picking took root during industrialization in the nineteenth century. Over the past half-century, waste picking has expanded vastly in the developing world due to urbanization, toxic colonialism and the global waste trade. Many cities only provide solid waste collection. Terminology Many terms are used to refer to people who salvage recyclables from the waste stream for sale or personal consumption. In English, these terms include rag picker, reclaimer, informal resource recoverer, binner, recycler, poacher, salvager, scavenger, and waste picker; in Spanish , , , , and ; and in Portuguese . A more contemporary term, focusing on the outcome of the professional activity, is "informal sector recycling". However, the word "informal" can be partly misleading, because in practice a continuum between total informality and proper organization in taxed registered formal activities may be encountered. In 2008, participants of the First World Conference of Waste Pickers chose to use the term "waste picker" for English usage to facilitate global communication. The term "scavenger" is also commonly used, but many waste pickers find it demeaning due to the implied comparison with animals. A waste picker is different from a waste collector because the waste collected by the latter may be destined for a landfill or incinerator, not necessarily for a recycling facility. "Dumpster diving" generally refers to the practice of anti-consumer and freegan activists who reclaim items such as food and clothes from the waste stream as a form of protest against consumer culture. "Waste picking" generally refers to activity motivated purely by economic need. Prevalence and demographics There is little reliable data about the number and demographics of waste pickers worldwide. Most academic research on waste pickers is qualitative rather than quantitative. Systematic large-scale data collection is difficult due to the profession's informal nature, porous borders, seasonally fluctuating workforce, and widely dispersed and mobile worksites. Also, many researchers are reluctant to produce quantitative data out of fear that it might be used to justify crackdowns on waste picking by authorities. Thus, the large-scale estimates that do exist are mainly extrapolations based on very small original research