Many people are distressed by the damage for-profit land development can do to communities. Formerly inexpensive and affordable properties are "upgraded" by expensive renovations or outright replacement, "gentrifying" them. "Gentrifying" is a euphemism for turning affordable housing (and the surrounding community) into a home for more affluent residents and driving out the original population. Think about driving all the lower middle-class workers off Manhattan Island and out of the more convenient areas of Brooklyn, for example. Community Land Trusts are a technique for collective or cooperative purchase of tracts of land (property and buildings) for co-operative ownership in perpetuity. Examples abound.