Members of the Varrio Sureno Town gang (defendants) regularly met, loitered, and caused various scenes in a four-block area of the City of San Jose (plaintiff) known as Rocksprings. The defendants continually obstructed Rocksprings residents’ enjoyment of their properties in many ways, including by dealing drugs, drinking in public, urinating in public, threatening the residents, shooting guns, fighting, using vulgarity, speaking loudly, playing loud music at all hours of the night, and using residents’ homes as escape routes and for hiding drugs. Overall, the gang’s presence in the area resulted in a “carnival-like atmosphere of collective mayhem” over an extended period of time. The City of San Jose brought suit against the 38 defendants for public nuisance. The trial court issued an injunction enjoining the defendants from several activities, including, “Standing, sitting, walking, driving, gathering or appearing anywhere in public view with any other defendant . . . or with any other known” gang member (paragraph (a)) and “confronting, intimidating, annoying harassing, threatening, challenging, provoking, assaulting and/or battering any residents or patrons, or visitors” of Rocksprings (paragraph (k)). The court of appeal reversed and invalidated these two provisions of the injunction. The California Supreme Court granted the city’s petition for review.