Web tracking explained using an example

You open Website 1 on your computer.
Website 1 displays an advertisement (yellow star). However, this advert does not come directly from Website 1 - your browser downloads it from the ad provider.

Browser downloads ad and sends fingerprint

When the advert is downloaded, data is exchanged in both directions:

  • When requesting the advert, your browser sends your fingerprint (green fingerprint for green computer) to the ad provider.
  • The ad provider sends you the advert (yellow star), which your browser shows on Website 1.

There are very few ad providers and these display adverts on many websites. Your browser therefore frequently calls up adverts from the same provider. Every time, you send your unique fingerprint to the provider. Now, if you log on to a page, the ad provider can match your computer’s fingerprint to you as a person, recognising you on all websites.

Tracker recognise your fingerprint on all websites

How can you prevent this?

It would now be useful to own a second computer with another fingerprint (here in red). If you never logged on to a website on this computer and only surfed sites covering particular topics, the ad provider could display adverts, but would not receive any information about the owner of the fingerprint.

Use different computers for different topics

You would then need to throw away this computer after you have surfed the net and buy a new one with a new fingerprint.

Too expensive? Too damaging to the environment?

Then use the PrivacyMachine!

The PrivacyMachine uses VM masks, which are simulated computers (virtual machines) that each create their own fingerprint.

Use virtual computer - with the PrivacyMachine

When you close a VM mask, all types of cookies are deleted (a “snapshot” of a virtual machine is produced again) and another fingerprint is created when the VM mask is started again (in picture: new colour replaces green).

An ad provider does not know if you are using two VM masks in parallel. However, the provider does recognise the connection between several browser tabs opened in one VM mask – until the entire VM mask is closed again.
This means that:

  • If you are in a VM mask and log on to an internet service, all pages in this VM mask can be connected to you as a person → even browser tabs that you have already closed.
  • If your internet searches can be divided into two different topics, e.g. checking Facebook and researching a doctor’s diagnosis, use two different VM masks. Every click on a link on your Facebook page can be matched to you as a person. A tip for external links: copy the link onto the clipboard and open it in another VM mask.