Mother Jones:

Since extra-virgin olive oil is the most valuable oil category in the United States, shady producers and dealers have plenty of incentive to mess with it in hopes of reaping more profit. They defraud consumers in three main ways: by (1) diluting real extra-virgin olive oil with less expensive oils, like soybean or sunflower oil; (2) diluting high-quality olive oil with low-quality olive oil; or (3) making low-quality extra-virgin olive oil.

When the University of California–Davis researchers tested olive oil bought off the shelf in 2010, they found that 69 percent of imported “extra-virgin” samples failed to meet international standards.

This story is all kinds of depressing. Since I’ve started to learn how to cook, I’ve fallen in love with olive oil. Depressing to know that the vast majority of what I’ve been using is adulterated at the very least and most likely an out and out fake at the very worst.