I have these reusable nets for fruits & veggies, and I always figured I'd encounter a cashier at some point, who'll say "Excuse me, you need to be destroying the environment, otherwise I cannot weigh these".

Thankfully, I have not yet (here in the Europes), but the self-checkout register at one of the shops genuinely has a step programmed in where it asks you, if you're using a reusable net or similar. If you click "Yes", it has the nerve to ask you to remove it before weighing. And it's just like:

Thankfully, self-checkout registers can be easily lied to, so I just tell it that my veggies are unpacked.