Tents are pitched illegally on a sidewalk in Seattle in January. The number of people sleeping outside in the city shot up by 20 percent in just the past year. David Ryder/Reuters /Landov hide caption

itoggle caption David Ryder/Reuters /Landov

The city of Hollywood, Fla., bought the Homeless Voice shelter from its owner, a longtime advocate for the homeless who agreed to stay away from the city for the next 30 years. Greg Allen hide caption

itoggle caption Greg Allen

Tony Simmons leads a group of Johns Hopkins University students on a "justice walk" in downtown Baltimore, during which they learn about public policy, providing services, and the connections between income inequality and health. Gabriella Demczuk for NPR hide caption

itoggle caption Gabriella Demczuk for NPR

Homeless advocate Arnold Abbott, 90, director of the nonprofit group Love Thy Neighbor Inc., prepares a salad Wednesday in the kitchen of The Sanctuary Church in Fort Lauderdale, Fla. Abbott was recently arrested, along with two pastors, for feeding the homeless in a Fort Lauderdale park. Lynne Sladky/AP hide caption

itoggle caption Lynne Sladky/AP

Los Angeles' Skid Row contains one of the largest concentrations of homeless people in the United States. Robyn Beck /AFP/Getty Images hide caption

itoggle caption Robyn Beck /AFP/Getty Images

This encampment under the Julia Tuttle Causeway in Miami, shown in 2008, was cleared out by authorities in 2009. It was home to sex offenders who were unable to find places where they were permitted to live under Miami-Dade County's strict residency law. Although this makeshift community was broken up, homeless sex offenders continue to camp out in other areas of the county. David Adame/AP hide caption

itoggle caption David Adame/AP

The homeless and others in need enjoy lunch at the Los Angeles Mission on Nov. 23, 2011, in celebration of Thanksgiving. Legislation to ban organizations from serving food to homeless people in public places has been proposed in Los Angeles. Frederic J. Brown/AFP/Getty Images hide caption

itoggle caption Frederic J. Brown/AFP/Getty Images

Officers Ned Bandoske (left) and Ernest Stevens are part of San Antonio's mental health squad — a six-person unit that answers the frequent emergency calls where mental illness may play a role. Jenny Gold/Kaiser Health News hide caption

itoggle caption Jenny Gold/Kaiser Health News

Lissette Encarnacion in her apartment at The Brook, a supportive housing complex in the New York City borough of the Bronx. Natalie Fertig/WNYC hide caption

itoggle caption Natalie Fertig/WNYC

Susan St. Amour panhandles on a median in Portland, Maine. The city tried to ban loitering on medians last year, but a judge found the law unconstitutional. Caroline Losneck for NPR hide caption

itoggle caption Caroline Losneck for NPR