Millions of Internet users rely on Adblock Plus daily to keep their web experience a relatively clean one. While it's a taboo practice with some companies that depend on the income raised by advertisements, it's an invaluable tool that cuts down on much of the "fat" that crops up during normal browsing.
Unfortunately, a few ads to tend to display here and there, whether it's relegated to a Wikipedia plea or an interstitial that forces you to view an ad before being given a link to access your original destination. Intriguingly enough, it appears that Google has a hand in keeping this practice afloat.
Adblock Plus comes with a filter that allows "acceptable ads" to slip through the cracks, effectively whitelisting specific advertisement -- namely, ads from Google and other large companies. This allows said ads to appear on a register of approved content that will be displayed despite browsers employing Adblock Plus.
While specific mention of Google's whitelisting practices is available in the Adblock FAQ, it still feels a little bizarre to see Adblock acting as a passthrough for consumers. Larger companies could effectively pay more to whitelist their ads, which opens up a whole new world of problems for the crowd wishing to further streamline their online experience.