I spend winter in tropical countries when cold/snow arrives in Canada, and stay there a few months, usually from November to April, every year. I used to leave Canada with Air Canada then transfer (connection) to an American airline such as Continental or AA, then to Costa Rica or Guatemala. But everytime, I went through the customs in cities such as Houston, Atlanta, Chicago, Miami, for a connection, I have been treated rudely by the agents. They are not polite, rough language, ask stupid questions such as "Why don't you study Spanish at home?", lack respect and inspect my luggage uselessly, (once 3 times my computer within one hour), Once I was not allowed to board because I had my toe on the yellow line. I sometimes felt being viewed and treated as a criminal. So to avoid these stressful connection flights, I take flights with NO stops in USA, that is, NO more american airline companies. In the last 4 years, I flew from and to Canada only with Copa or Taca Airlines who give me a very relaxed trip with services such as extra luggage and in-flight free meals, thus avoiding american stopovers. They are Star Alliance partners with Air Canada.I know many Canadians who also avoid stopovers in USA. Now I travel with security, respect and peace of mind.