Can a supermarket check your bag?

Questioner

Can a supermarket (from a privacy point of view) just look into your private bag (so not a shopping bag but your bag that only contains your private belongings) because they have a picture on the door?

Lawyer

In principle, this is allowed if it is clearly stated what the house rules of the store are and that checking bags is allowed. Private bags may also be checked. A store is not a public space and the shopkeeper can set rules for this himself. If you do not want your bag to be checked, you will be denied access to the store and you are free to go to another store.