The mortgage crisis has spawned an unusual federal class action by African-Americans in Antioch, Calif., a San Francisco suburb, alleging city intimidation and harassment of minorities who rent homes using federally subsidized Section 8 housing vouchers in an effort to force them out of the area.

“There is no question that the city and its police department are targeting Section 8 families, particularly African-American recipients,” said Brad Seligman of the Impact Fund, a public interest law firm in Emeryville, Calif.