A San Francisco law school, business owners and local residents are suing the city to force it to clean up the Tenderloin neighborhood — alleging an almost 300 percent spike in homeless shanty towns, drug dealing and feces-covered sidewalks have made conditions “insufferable.” The lawsuit, filed in federal court May 4 by a group of plaintiffs led by the University of California Hastings College of the Law, seeks a court order to stop the city from using the neighborhood as a “containment zone” for homeless encampments. “Open-air drug sales and other criminal activity, plus crowds of drug users and sidewalk-blocking...