Melanie Trottman reports on consumer safety issues. Seven major U.S. public-interest groups put President-elect Barack Obama on alert Thursday: They’ve united to redouble their efforts to strengthen consumer protections, including a call for a White House consumer czar. “Consumers should have a voice at the President’s ear,” the groups wrote in a letter addressed to Obama, Senate Majority Leader Harry Reid and House Speaker Nancy Pelosi . “As the events of recent months have shown, ...