REUTERS/Robert Galbraith Canada and Australia have acute housing bubbles forming. There is an idea spreading that the US mortgage crisis happened because people could legally just walk away from their mortgages. Banks have different regulations to follow depending on where in the world they are located, but this is wrong. When a housing downturn gets big enough, there will be a mortgage crisis, and it will hit banks, shadow banks, and mortgage insurers no matter what the mortgage laws are: that’s what the US mortgage crisis has demonstrated.