No, it hasn't been explained to us by the Government of Canada what that would entail, and perhaps, in fairness, it wouldn't be the Government of Canada that would be doing the extra screening. But one of issues that arises is the extra screening could involve questions in order to determine whether or not the person trying to board an aircraft or acquire a boarding pass is in fact the same person who is on a watch list or a no-fly list. That could include asking questions that would help determine whether or not, to use the famous example, this is the Edward Kennedy that's on the watch list, or is it in fact the late senator, who experienced significant problems.
There is a historic problem with the American no-fly list of confusion over names, and some of the additional screening would be to resolve that. The screening could also be questions about where you intend to travel and what your future travel plans are.