People outside of Italy are probably not aware of how seriously they take the topic of olive oil over there. The label "extra vergine" increases the price so much that there is a huge economic incentive for fraud. To combat this they have a taste police (literally) that checks that olive oil samples are not secretly mixes of fresh and old oil together. They are... quite opinionated, as you can see this exchange from…
From Olive Oil's Dark Side [0]: "The Romans instituted elaborate mechanisms to prevent fraud. [...] These careful records were intended to prevent the siphoning off of oil en route, or the substitution of an inferior product."
The whole article is very interesting!
[0] https://www.newyorker.com/books/page-turner/olive-oils-dark-...