Customs Canada has started treating Americans, the same way US Customs treats Canadians — poorly. The concern on criminal records is mostly felonies and certain types of misdemeanors. But what makes it worse for Americans is that most misdemeanors in the US (things like drunk driving, reckless driving, some traffic accidents with injuries, some fish and game convictions), are considered felonies in Canada. If you have any conviction for anything, you may have a problem.