Going through the supermarket with a backpack instead of a shopping cart – is that allowed? Branch manager explains. Going through supermarket with private bag while shopping is punishable: branch manager explains on TikTok.
Cloth bags and shopping bags are in a gray area. It's safest to simply put your purchases in a private bag at checkout. If theft is suspected, a store detective may ask to check your bags. The supermarket is not allowed to search their private bags without consent. So you're on the safe side with a shopping basket or a bag that offers visibility.