Thank you for the question.
Section 40.1 of the Canada Post Corporation Act indicates that when a letter is in the postal system, it cannot be opened by anybody other than the person to whom the letter is addressed. Because of that, a potential gap has been identified. There is a possibility for people to use letter mail to ship small quantities of potentially nefarious products. Even with a warrant, a law enforcement official would not get access to that letter. The proposed adjustments, if they go forward, would enable letters to be seized when necessary, as long as this is undertaken in compliance with another act, such as the Criminal Code or the Controlled Drugs and Substances Act.
It's to try to address what is seen as a potential issue, because even an inspector within Canada Post cannot open a letter while it's in the system of Canada Post.