Here in Toronto, the previous Mayor and council introduced a "fee" on plastic bags (good move) in stores of $0.05, with the money going to the store (dumb move). This has resulted in many MANY people using reusable bags.
Of course the current Mayor is of the opinion this is foolish and I believe (but might be wrong) is considering dropping this fee
I will admit I do every few weeks buy 20 bags; this is however because I volunteer doing Meals on Wheels 5 days a week, and at times, when clients are not home, leave meals in bags on their door step.