Legal Question in Civil Litigation in California

Ask for a receipt or claim check. If they won't give you one, don't shop there. Consider getting a locking briefcase or backpack.

By requiring you to leave your briefcase or backpack, they are creating a bailment which makes them completely responsible for the item to the extent they are aware of and voluntarily take on responsiblity for the value of the item. So you can't give them a ratty old backpack with a 10kt diamond in it and hold them responsible for the value of the diamond if it is lost or stolen. You can tell them what is in your briefcase and the value, but without any proof, it is a he said she said about whether you properly and clearly declared the value of the item and they knowingly and willingly undertook the bailment of your valuable items. As for discrimination, they are entitled to discriminate on the basis of the size of the container, but they technically cannot make you leave a bag the size of a purse at the counter, while allowing a purse the same size or larger into the store. Of course if you're rich enough to take that one to court, you probably don't care whether they lose your laptop, right?