 This is the source of the housing market's power, the grip that keeps property owners vigilant, insecure, and on edge, and in too many cases, oblivious or hostile to the needs of others, as the Not In My Backyard or NIMBY movement shows. Insecurity prods us to care which direction the arrow points on the app, and that prevents us from realizing that security may be better gained another way, not by going it alone, but by providing for one another.