There is some common sense applied to this. If you are trying to scan a printed barcode, then the reader or handheld device must be able to see it. So that's scanning through walls and doors out of the question! 

However, if your product has been collated onto a pallet and then shrink wrapped this is a valid question. Some scanners are better than others (again, you get what you pay for).There will be more available on this functionality very soon....