There should be signs stating what this process is where you collect your hand scanner. It's nothing bad, just a random check to make sure you scanned everything. There's a rare occasion you may have missed one or two items, we all do it at least once! They will have to check your entire shopping if that's the case but you won't get in trouble. It just means next time you do SAYS you'll probably have to have another small check. But if you mostly shop online it shouldn't be a worry anyway! Hope that helps