Signature for sending packages from Canada?

Hello, and Happy Boxing Day. This is an appropriate story to tell on Boxing Day, a holiday celebrated in Canada. (The "boxing" refers to boxes, as in presents, not Muhammad Ali.)

Since I was good this year, I received the "Twitch City" DVD set I had recently mentioned. My mother, who gave me the present, told me the post office wanted her to sign for the package. She said they told her she had to come down and sign for the package because it was sent from Canada (it came from amazon.ca). They told her the procedure was necessary due to Homeland Security rules.

I didn't realize packages from Amazon.ca fell under potential terrorist concerns. Let me assure Homeland Security and all of you that the package contained only the complete DVD collection of the "Twitch City" series and nothing more.