Prime Minister Justin Trudeau has threatened to tax Canadian grocers in a bid to lower grocery costs for families nationwide. "Large grocery chains are making record profits," he claimed Thursday. "Those profits should not be made on the backs of people struggling to feed their families." While at the Liberal caucus retreat in London, Ontario, Trudeau demanded that grocers devise a plan to stabilize prices by Thanksgiving. Otherwise, tax measures may be on the way for Loblaw, Metro, Empire, Walmart and Costco. Industry Minister Francois-Philippe Champagne said the feds would also engage with other actors in the food industry. "We're...