Odd experience recently leaving YYC for LHR - after the final boarding check and on the way to the aircraft, a couple of CBSA officers were stopping all passengers.

"Just a routine check to see how much Canadian currency you're carrying out of the country today?"

"Umm, a couple of hundred dollars I guess?"

"Okay, thank you. Have a nice flight."

They weren't writing anything down, just questioning everyone. Was this a cover for something else, or do CBSA really ask people how much cash they're carrying and then just believe the answers and not take records?