[xkeysc0re]

I am not a printer company executive nor an employee of a federal agency (I swear!), so I couldn't tell you precisely the logic behind it. My venture is that while it's true there are lots of physical safeguards to prevent the spread of counterfeits, these dots and other stenographic techniques can be used in investigations to trace the source. If you know what printer was used and what serial it has, you could theoretically track it through the vendor's supply chains.

I also believe that international trade agreements and banking regulations, such as the Japanese measures mentioned in the article, require dots and similar methods even if they have perhaps technically been superseded.