I grew up in a country where this was impossible. It's quite easy to render this ineffective. This is about the same as getting a free refill from a soda fount

I grew up in a country where this was impossible. It's quite easy to render this ineffective. This is about the same as getting a free refill from a soda fountain at a place that doesn't explicitly post that they allow free refills. If they object, the soda fountain can be relocated behind the counter with few issues or inconvenience to just about anyone.