European regulators have published an opinion arguing that website operators should disclose all methods employed to track consumers around the Web, instead of only having to inform visitors when they're being tracked via "cookies."

The move demonstrates the difficulty with which policies attempt to keep pace with technical innovations. Website operators started employing alternatives to cookie-based tracking tools in earnest after regulators required their disclosure to consumers in 2012. Now they're being told to disclose the use of these "silent trackers," much to their chagrin.

It also shows how privacy is often regarded as a bug instead of a feature. Facebook showed something similar when it revealed an updated version of its Atlas advertising platform earlier this year, which allows the social network to track Internet users across multiple devices. As I wrote back when the update was first revealed by the Wall Street Journal:

Being able to browse around the Web without having to worry about advertisers connecting the dots between viewing an advertisement on a smartphone and purchasing something on a laptop was just a fluke. Now this new ad network is going to be “correcting the error,” so to speak.

Welcome to the modern era, where even a modicum of privacy is viewed as a technical failing that’s going to be solved by some company or another to appease the almighty advertisers. It's clear that cookies aren't the only tools used to track consumers online. This opinion doesn't represent a shift in regulators' views so much as it lays the groundwork for them to remain relevant while companies develop other, potentially more intrusive tracking systems, often without revealing their existence to millions (or billions) of consumers.

And make no mistake: these tracking systems are nigh-ubiquitous. I learned of this new opinion via the Guardian, and a privacy-focused Web browser, Epic, showed that seven tracking tools were used on the article page alone. The Guardian's homepage supports even more trackers from Adobe, Twitter, Google, and other companies. A quick glance at the stats provided for a Pando article show that some 32 trackers were active. These tools are everywhere.