After a quick YQT Easter weekend, I have a question about how AC handles boarding passes:

On Sunday, I flew YQT-YYZ-ORD-GRR. On the two AC segments, the F/As on board the aircraft ripped the small part of the card (on the right) as I entered. They had a whole stack of them sitting there, from each passenger, I assume. I have never noticed this before and it certainly was not the case when I flew up on Thursday or on any of my other flights last month.

Would this be to sort out passengers seated in the wrong area (couldn't they just ask to see the BP) or to reconcile pax numbers on-board? Is this a new procedure (did I miss something? ) or is it individual lead F/A preference? Maybe A Flygirl, CPYVR, or some of the others could shed some light? Thanks!