In the days before unlimited long distance services it was the phone company that pulled this sort of low level trickery and depended on volume to make it profitable. Every month you would find little a fifty or sixty cent long distance call to a number I didn’t recognize. Most people never noticed it, those who did didn’t bother to investigate it since it was so little. But when they did that to thousands of customers, month after month, the take soon became pretty hefty.
I never saw official proof it was going on, but I sure noticed there was always at least one call on my bill that I was sure we hadn’t made.
Same thing with gas pumps that click off a few pennies before the gas flows.