Squatting has a long history, as old as or older than the idea of property itself. To squat in many countries is in itself a crime; in others it is only seen as a civil conflict between the owner and the occupants. Property law and the state have traditionally favored the property owner. However, in many cases where squatters had de facto ownership, laws have been changed to legitimize their status. It is said that the United States Homestead Act is an example of such legislation. Additionally, US states which have a shortage of housing tend to tolerate squatters in property awaiting redevelopment until the developer is ready to begin work; however, at that point the laws tend to be enforced.

Urban migration has driven global estimates of the number of squatters over one billion people, with 200,000 added every day. In many of the world's poorer countries there are extensive slums or shanty towns, such as the favelas of Brazil, typically built on the edges of major cities and consisting almost entirely of self-constructed housing built on terrain seized and occupied illegally. Also, common in many of these same countries are rural squatter movements, such as, again taking a Brazilian example, the Landless Workers' Movement.

Besides being residences, a few squats are hosts to give-away shops, pirate radio stations and even cafés.