Simpson's Paradox as per this article shows the danger of looking for data that fits your agenda. You can take almost any set of data, twist and contort it to your liking, and present it as fact. Leave a variable out as shown and there is instant bias. If it doesn't fit your needs you can introduce another variable outside of the set to produce a favorable outcome. Present your view with the "facts" and let the controversy begin.

If care isn't taken this can potentially cause a company to fail or on a much larger scale cause national false news. (shameful use of this years new buzz phrase)