Thousands of Ontario education workers hit picket lines across the province honking noisemakers, waving flags and chanting "stand up, fight back," on the first day of an indefinite walkout that's shut many schools. The Progressive Conservative government enacted a law imposing a contract on 55,000 education workers represented by the Canadian Union of Public Employees and banned them from striking, pre-emptively using the notwithstanding clause to guard against constitutional challenges.