Ya do that. I was under the understanding from a person that works at a post office for Canada Post, that they or their employees cannot open a package. They do have to report anything suspect to the authorities. The CBSA is a separate entity, and is actually considered a part of national security. Their officers "must" check anything coming into the country within reason. An airport has different laws however. They have security personnel that checks packages going into flight, but once again they are not employees of the airlines or Canada post. As for the person running the X-ray machine, or other devises like that, I'm not sure what the legislation on them is.
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