No, it appears Cracked have got the real story confused.
There are two different issues:
- the adulteration of expensive olive oil with cheaper sunflower oil.
- the adulteration of expensive grades olive oils with cheaper grades of olive oil
@Laurel's answer gives a good description of individual instances of the first issue. That shows it is a real problem.
However, that's quite different to Cracked's claim that "Today, the stuff that is pawned off to us as quality olive oil is often just a tiny amount of the real thing [...]"
The UC Davis Olive Center does research (with industry links) into olives and olive oil. For many years, they have been testing olive oils being sold in California for years to determine if they meet various standards, and they are somewhat critical of the purity of Extra-Virgin Olive Oils.
Their 2011 report, Evaluation of Extra-Virgin Olive Oil Sold in California said:
While there are many excellent imported and domestic extra virgin olive oils available in California, our findings
indicate that the quality level of the largest imported brand names is inconsistent at best, and that most of the topselling
olive oil brands we examined regularly failed to meet international standards for extra virgin olive oil. [...] Of the five top-selling imported “extra virgin” olive oil brands in the United States, 73 percent of the samples
failed the IOC sensory standards for extra virgin olive oils analyzed by two IOC-accredited sensory panels.
But the reasons they gave for the failures did not include that it was adulterated with sunflower oil:
Our testing indicated that the samples failed extra virgin olive oil standards for reasons that include one or more of the following: (a) oxidation by exposure to elevated temperatures, light, and/or aging; (b) adulteration with cheaper
refined olive oil; and (c) poor quality oil made from damaged and overripe olives, processing flaws, and/or improper oil storage.
Snopes draws a similar conclusion:
The tested samples did not always meet the stringent extra-virgin standards for taste, aroma, and color, and the flavor profiles of some olive oils were likely overstated, but the samples were not oils produced from another source masquerading as olive oil, nor did the study raise concerns about purity, adulteration, safety, or substitution of various brands of olive oils.)
Laurel's answer shows that there is indeed historical evidence of a problem with non-olive oils being mixed in with olive oils.
The UC Davis report shows that there is indeed a problem with cheaper grades of olive oils being mixed in with more expensive ones.
However, the UC Davis report also shows that the former issue is not common, and the second issue is (in California, at least).