Windsor, Ont., just across the Canadian border from Detroit, has always been a refuge for Americans whose proclivities run counter to the prevailing laws of the U.S. In the mid-1800s, runaway slaves made their way to freedom there via the Underground Railroad. During Prohibition, Al Capone's boys smuggled rum from Windsor. And rebels are still attracted to Windsor. These days, though, they come not for liberty or libations but to buy toilets.
This new flow of contraband south from Windsor began in the name of water conservation. In the Energy Policy and Conservation Act, passed in 1994, Congress mandated that toilets...