In Toronto, about 10-15 years ago, they started to tax plastic bags 5¢ each when they were free in the suburbs, but retailers then started to charge the own bag tax across the country. Some stores said that their profits were returned to environmental projects, but it was absolutely clear that the larger grocery stores just pocketed extra profits.

Plastic bags are now banned in many towns and cities, including City of Montreal. You gotta bring your own reusable bags.