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