Wal-Mart faces a potential labor injunction from a union group asking the company to rehire all 2,200 employees affected by the abrupt temporary closing of five stores a week ago. One affected store, in Pico Rivera, California, has been a hotbed for worker protests against Wal-Mart. A union is asking labor regulators to go to court to force Wal-Mart to rehire all 2,200 employees affected by the abrupt temporary closing of five stores a week ago. The United Food and Commercial Workers International Union filed the charge on behalf of OUR Walmart with the National Labor Relations Board on Monday,...