Union members set up a blockade outside General Motors' Canadian headquarters on Wednesday, a day after the automaker announced it was halting production at four factories across North America. - "Nobody is going into GM’s head office as long as we're standing here today," Canadian Auto Workers Local 222 president Chris Buckley told CBC News, noting that workers have been allowed to cross the blockade on foot, but not with their vehicles. - GM CEO Rick Wagoner was to meet with CAW president Buzz Hargrove on Friday, but Buckley said the blockade will remain in place. He said the union wants GM to reverse its decision, which will leave about 2,600 employees out of work. - "This decision will have an absolutely devastating impact, not only on 2,600 of my members, but throughout this community, throughout our province." - The Oshawa plant, which produces the Chevrolet Silverado and the GMC Sierra, is expected to close in 2009, GM CEO Rick...