The Supreme Court of Canada has drawn that line of balance between privacy and safety. That line is about necessity. So the information that is collected must be necessary to serve the public safety objective it serves, as well as proper attention to the reasonable expectation of privacy. That is contextual, and the context will determine how the intrusion is valid or not.
We need, in the area of national security, to exercise a certain amount of deference for the very reasons that you invoke. The courts have stated as much. In our thinking we apply the principles that have been issued by the Supreme Court of Canada and other tribunals in Canada.