Every time you use Google or Facebook without being logged into any of your accounts, cookies are stored on your local system.
They are anonymous but even they reveal information about your browsing habits to the service that sent them to you.
Google , for example, knows what you've searched for, but it can't link the information to you as a person. The company states in its privacy policy that it uses anonymous identifiers.
The same goes for Facebook , which can record the websites you visit from the Facebook widgets they use, but cannot link the information to your account.
If after your anonymous browsing you decide to log in to an account, all the previous activities you performed as “anonymous” will be recorded in the account you used to log in. This happens because Google and Facebook use the same root domain cookie to track anonymous and logged-in users.
For example, Google may know that you visited iGuRu.gr, even if you are sure that you searched for it on the service, while you were not logged into any of your Google accounts before accessing our website. The same applies to Facebook, which knows which sites you visit if they use widgets, apis or other elements from Google or Facebook domains.
This essentially means that the data these companies collect about you is anonymous only if you have never into an account on these websites, block all third-party requests from these companies by default, or delete the cookies they have stored on your computer regularly and especially before logging in or out of your account.
The first option sounds easy enough. You can use two different browsers for this, or use both private and regular browsing mode using a single browser.
Blocking third-party requests can be done using add-ons, such as NoScript for Firefox or Scriptsafe for Chrome.
Deleting cookies also requires add-ons. While you can set the web browsers you use to delete cookies automatically upon exit, you can also delete them yourself (Firefox, Chrome), but it is quite time-consuming.
You can also use a Firefox extension, such as Self-Destructing Cookies , to delete your cookies as soon as you leave the site that has stored them on your computer.
Please note that this also applies to other companies and services, but most often to a lesser extent than Google and Facebook as the two sites are very popular on the Internet.
