Seminole, your comments outline one reason why Canadians get annoyed at CLT. They are using a form explicitly not designed for Canadians (the I-94), and one that no other point of entry seems to use and applying it ad hoc. If the US wanted to require Canadians generally to fill out I-94s, that is the US government's option and would at least be consistent and provide fair warning to Canadians that they really do need to keep form I-94C (a Canuck version). Of course, many people would likely choose not to travel to the US in response. But having just one port of entry trying to use a form that might simply be thrown out if you hand it in at any other place (E.G. fly out of SEA) is simply inane and likely to generate many false positives.