heard on his case. Sinclair's unexpected release came two days after a large "Free John" benefit concert, with performances from John Lennon, Yoko Ono, Bob Seger, and Stevie Wonder, was held at the University of Michigan's Crisler Arena. Legal reforms The group had a direct role in two important legal decisions. A landmark U.S. Supreme Court decision in 1972 quashed Plamondon's conviction and destroyed the case against John Sinclair. The court ruled warrantless wiretapping was unlawful under the U.S. Constitution, even in the case where national security, as defined by the executive branch, was in danger. The White Panthers had been charged with conspiring to destroy government property and evidence used to convict Plamondon was acquired through wiretaps not submitted to judicial approval. The case U.S. vs. U.S. District Court (Plamondon et al.), 407 U.S. 297, commonly known as the Keith Case, held that the Fourth Amendment shielded private speech from surveillance unless a warrant had been granted, and that the "warrant procedure would not frustrate the legitimate purposes of domestic security searches." The judgment freed Plamondon, yet John Sinclair was free only on bond fighting his possession conviction. In 1972, the Michigan Supreme Court ruled in the People v. Sinclair, 387 Mich. 91, 194 N.W.2d 878 (1972) that Michigan's classification of marijuana was unconstitutional, in effect decriminalizing possession until a new law conforming to the ruling was passed by the Michigan Legislature a week later. Sinclair was freed but the cumulative effects of the imprisonment had marked the end of the White Panther Party in Michigan, which renamed itself the Rainbow People's Party while John Sinclair and Plamondon were in prison. The Rainbow People's Party, headquartered in Ann Arbor, disbanded in 1973. Portland The headquarters of the White Panthers in Portland, Oregon were raided by the FBI on December 5, 1970. Two members of the group were arrested and accused of throwing a molotov cocktail through the window of a local Selective Service office. San Francisco White Panther Party chapters in San Francisco, Marin and Berkeley remained active into the 1980s. The WPP ran a successful 'Food Conspiracy' that provided groceries to about 5,000 Bay Area residents at low cost, due to bulk buying and minimum markup. The White Panthers held People's Ballroom in the Park concerts in Golden Gate Park. In 1983, angry because then-Mayor of San Francisco Dianne Feinstein proposed to ban handguns in the city, the