In The Untouchables, which is set during the Prohibition period in the U.S., cartons of liquor are found by the authorities. On these boxes are stamped a huge red maple leaf to indicate (presumably) that they're Canadian. But although the maple leaf was a symbol of Canada for a long time, this particular stylized maple leaf (seen on the modern day Canadian flag) is an ugly design of the 1960s rather than the 1920s and looks like no real maple leaf ever did. In the 1920s Canadians used a more realistic looking symbolic maple leaf, for example, on their Olympic uniforms. I seem to remember a modern Canadian flag appearing in the movie also, but may be wrong on this. The Maple Leaf was only made the flag of Canada in 1965. Prior to that the Canadian flag was the Red Duster (Union Jack in the corner of a red flag with the Canadian coat of arms in the centre).