I don't know whether in your country had this problem but there certainly are some example in my country. Malls are still using plastic bags when cutomers are buying things. So, as I said, we need to stop this. This is the time customer should say NO towards plastic bags. And I don't know why, it came to me as a natural because I will think that plastic bag will be an object that occupy some space at home, so I don't like to take plastic bags except when I REALLY need it. When you buy the things, if it is really not that much, please just say no to the cashier. They will also be please enough not to give out the plastic bags because this will 'save their energy by packaging' and save the company's cost. I had this habbit, but i think everyone should do the same. If can, please carry a bag along. When you buy the things, just take the receipt and put the stuff inside your bag. You won't look suspicious with the receipt, I bet.