Since Edward Snowden proved the American and British governments had instigated a snooping free-for-all, privacy has been a fraught issue on the internet. But it's not just nation states that are out to steal secrets - companies are at it too, and they do it using trackers.
When your staff are browsing the internet they encounter bits of code across different sites. These may take the form of adverts, or even social media buttons imploring you to share the site's content, but they are all trackers.
Bumping into the same trackers again and again is like bumping into the same marketing executive everywhere you go - before long he'll have a decent idea of your habits and interests. Companies are building up big data so they can flog you their products as effectively as possible, and they aren't much interested in protecting your privacy.
If this bothers you, then it's time to become acquainted with tracker blockers. These come as extensions for Chrome or Firefox than can be installed with a couple of clicks. Once set up they monitor incoming traffic, blocking the stuff you don't want and approving the stuff you do.
The trouble is that it was very hard to find out whether the blockers did what they said - until Raymond Hill, creator of the blocker HTTP Switchboard, decided to explore further. The result is a browser session benchmarker, a simple tool for Chrome and its open-source counterpart, Chromium.
Hill measured how the tracker blockers stacked up against one another, testing his own software on two settings, as well as Adblock Plus, Ghostery, Disconnect, and the recently released Privacy Badger beta. With each plugin enabled in turn, he surfed the 15 most popular news sites on the web to see how many third-party scripts, domains and cookies were running in the background.
Credit: Raymond Hill
The first thing to remember is that unlike other extensions, Privacy Badger does not rely on a universal blacklist, but reacts to behaviour as the user browses. As Hill says in his notes, his installation of Privacy Badger was not primed beforehand, so in future benchmarks it is likely to fare better.
HTTP Switchboard was tested under two settings: block all/allow exceptionally (BA/AX), and allow all/block exceptionally (AA/BX). The former is enabled by default, while the latter relies on a preset blacklist. Unsurprisingly, blocking everything is the best way to guarantee nobody is watching you.
The results are interesting for two reasons. First, it shows just how much potential snooping is taking place on some of the web's most frequented sites. Second, HTTP Switchboard is clearly the tinfoil hat-wearer's blocker of choice.