Certain grocery chains in Canada employ these types of self checkout scanners. Every item is weighed, your bags need to be on the scale from the start and there’s a camera over each checkout.

Yes you do have to put your bag in a special place. If you dont, and the item you scanned (which they already know much it weighs) wont add to the total weight of the scales and it won’t let you scan another item or pay.

It’s effectively impossible to accidentally steal something.