Strictly speaking that's been one of the card rules for a long time - you were supposed to swipe your own card in stores and absolutely never let a waiter wander off with it.
Locally (in some stores around here), cashiers were required to swipe cards for Visa (because they also have to check your signature, etc.).
Nowadays in Canada though, no one uses swipe cards anymore, it's all chip-and-PIN. The only time anyone swipes my card is when I go down to Seattle, and it's really unnerving when they do so.
In fact my impression is that in the vast majority of stores now you swipe your own card. The cashier never touches it.