This is an interesting article on those store policies that harass their customers and treat them like criminals, and what you can do about it.
If you possess an ounce of personal pride or perhaps two ounces of fortitude, then the 100 percent correct move is to proceed immediately out the door. Why? There are many reasons, chief among them being that rational adults should not instantly obey mechanical voices (unless that voice instructs us to exit a burning aircraft). Also, if you haven’t stolen anything and therefore do not require interrogation, there is absolutely nothing that should compel you to linger post-transaction. It’s depressing enough simply being there in the first place. Another good reason to make a quick exit is that you aren’t being paid to assist some giant retailer with its security measures. You aren’t part of the team, and you didn’t clock in. The clearest reason for leaving the store, however, is that there exists absolutely no legal obligation to remain there, and the store has no right to detain you.
Here’s an older account by a Best Buy shopper who refused to stop and show his receipt at the door after having paid for his merchandise. Be sure to read the epilogue as well for some interesting responses.
But this verification step is purely voluntary. Merchants basically have two rights covering people entering and exiting their stores. They can refuse to let you enter the premises and/or to sell you anything, and they can place you under citizens arrest for attempting to leave the premises with any property that you haven’t paid for. But the second you hand over the appropriate amount of cash, they lose all rights to the items. They can’t legally impair you from leaving the store with your property.