Wednesday, 23 November 2016

Stop online advertisers tracking you

Stop online advertisers tracking you

The web is tracking you without you even knowing. Mike Plant explains how to shield yourself from online advertisers that want to sell your browsing habits to the highest bidder

Are you being watched right now? Probably not because you’re reading this! But the next time you go online your activity will be closely monitored. Every website you access employs trackers designed to see how you reached it, which bit of the site you interacted with, how long you stayed put and what site you leapt to afterwards.

Using this information website owners build up a profile of you that is used to tailor the adverts you see. They sell this to tracking companies who will, in turn, re-sell your data. That’s why you end up seeing adverts for items you’ve just been looking at seemingly wherever you browse. The good news is you don’t have to put up with such tracking. Lightbeam, Privacy Badger and Ghostery are all browser extensions that can track and even shield you from advertisers. Here, we explain how to use them.

See trackers at a glance

Lightbeam was developed by Mozilla (the same organisation that owns Firefox), which is why it’s only available as an extension for Firefox at the moment. To install it, open Firefox, go to and click ‘Add to Firefox’, followed by Install. Then open it by clicking the Lightbeam extension’s icon at the top-left of the browser window. Lightbeam only works from the moment you install it, so it won’t look at your browsing history. It quickly starts showing you how many tracking websites are watching what you do online.

Not to pick on one popular website in particular, we decided to visit three after installing Lightbeam:, (Mail Online) and One of Lightbeam’s unique features is the way it displays online tracking as a graphic. In this way you can see at a glance how many trackers certain websites use and who they share your profile with. For example, it was clear that Mail Online and Microsoft have a tracker in common – in this case BlueKai, a company that specialises in selling your data.

As you use Lightbeam you’ll see that the visualisation continues to grow as more websites and trackers are added to it. Websites are represented by their logos in circles, while trackers are displayed in triangles. To see a list of all trackers used by a website, click its logo. Mail Online, for example, has 23 trackers watching visitors to its site, Microsoft 27 and the BBC has eight. That’s to be expected as trackers are usually linked to adverts and the BBC is ad-free.

To block any tracker, click its icon, then click Block Site. However, rather than do this using Lightbeam we suggest you use another browser extension – Privacy Badger.

Block trackers automatically

Privacy Badger is available as an extension for Firefox and Chrome (there’s no Internet Explorer or Edge version). Like Lightbeam it monitors trackers while you browse, but goes further by automatically blocking trackers that are monitoring you across multiple websites, effectively hiding you from those advertisers.

To install Privacy Badger go to and click ‘Click here for Firefox version’ or ‘Click here for Chrome version’ (depending on your browser), and click Install (Firefox) or ‘Add extension’ (Chrome). Once installed the extension will add a badger icon to the top-right of the browser window.

Once you’ve visited several websites, click the icon and then the Settings button (it looks like a badger). Click the Filter Settings tab to see a log of the trackers Privacy Badger has detected so far. Each tracker (Privacy Badger calls them ‘tracking domains’) will have a slider to its right that’s either green (allowed), yellow (allowed without cookies) or red (blocked).

You’ll notice they’re mostly green when you start, but Privacy Badger will start to change these to yellow and then red as you browse. If a tracker turns from green it means that Privacy Badger has detected it on a number of sites and is putting a stop to its snooping. In effect, it keeps your data private by blocking all cookies and internet code associated with those trackers.

Green trackers are deemed “unobjectionable” by Privacy Badger, which means they haven’t been spotted across “multiple websites”, and are therefore less likely to share your data. Yellow indicates a tracker that exists on multiple sites but is necessary for a website to display correctly. In this situation Privacy Badger will block the cookies from these trackers to limit the information that tracker can glean from your browser. Anything marked red is completely blocked.

As you browse, Privacy Badger will update the list and adjust the sliders to hide you from advertising trackers. You can override the settings by manually moving the sliders. This might be necessary if you find certain websites aren’t displaying correctly, or online games you usually play suddenly stop working, though we didn’t run into any problems while using the extension.

A useful knock-on effect of Privacy Badger is that it also acts as an ad blocker. That’s because trackers are usually contained within the HTML code or images that create the adverts on websites, so by blocking the tracker the advert will be blocked too.

Block trackers in Internet Explorer

So far we’ve covered extensions for Chrome and Firefox only, but another extension, Ghostery, does a similar job on Internet Explorer. Go to and click ‘Add to Internet Explorer’, then Run when the pop-up bar appears at the bottom of the screen. This opens the Ghostery installer. Click Install, then follow the instructions. We opted for ‘No thanks’ at the Help Keep Ghostery Free donation page (but the choice is yours) and chose to block ‘Advertising trackers’ on the Blocking page. Ghostery is also available for Firefox and Chrome using the above link. Edge doesn’t currently have an extension to monitor trackers, though Privacy Badger is working on a version for the browser.

Ghostery works a little differently to Privacy Badger in that you have to visit a specific page, then click its icon (the Ghost at the top-right of the browser window) to see all trackers associated with that website. For example, Ghostery detected 19 trackers on the Mail Online website – the number differs from Lightbeam because the extensions and browsers all work slightly differently. Most trackers were already blocked because of the advertising settings we applied during set up.

To check those settings, click the Ghostery extension, then the Settings (cog) icon and click Options and scroll to the Blocking Options section. You can change the settings by moving the slider next to each tracker to the left (to allow it) or right (to block it).

Ghostery is regularly updated by its developer with the latest lists of trackers – and suggestions as to whether you should block them. Annoyingly, these suggestions aren’t applied automatically. To change that go back to Options and click the Advanced tab. In the Auto Update section, tick ‘Block new elements by default’, then click Save.


BlueKai (now owned by Oracle) is a name you’ll see often when you check the trackers on websites. It’s one of the biggest trackers of online data, which means it almost certainly has an idea of the sites you access, your interests and what you buy. You can see what the tracker knows about you by visiting Scroll down the page to the ‘Step 1. Review’ section to see the information BlueKai has on you. In our case it had 17 pages of profiling on our Hobbies & Interests. Blocking BlueKai using any of the extensions recommended in this feature is a good way to prevent more of your information being captured. To opt out, go to and click the orange Opt Out button.