I will start the set of articles about privacy with something simple: avoiding cookies from third parties. So, let’s remind what is a cookie.
Cookies not for eating
Citing wikipedia, we have:
A cookie, also known as an HTTP cookie, web cookie, or browser cookie, is used for an origin website to send state information to a user’s browser and for the browser to return the state information to the origin site. The state information can be used for authentication, identification of a user session, user’s preferences, shopping cart contents, or anything else that can be accomplished through storing text data on the user’s computer.
The part about user’s preferences and shopping cart sounds quite useful, doesn’t it? Actually, cookies are useful. Thanks to them we can autologin to sites where we have logged in before, keep our preferences if the website has some personalization, etc. So, the concept is not completely evil. If you visit a site and accept their cookies, you’re accepting that they keep track of you in exchange of some services.
Cookies from strangers
So, we agree on accepting cookies from a website, but do you know that by default you are also accepting cookies from other sites apart from the one you are visiting? Maybe the website you are visiting has ads, from a third party, and these ads are storing cookies in your PC so that they can track you. Or if it has a Like button from Facebook (like I have in the blog… should I remove it?), Facebook is using it to put a cookie on your browser to track you even if you are not in the social network. These cookies are called Third Party Cookies, because they don’t belong to the domain/website you are visiting.
Do not eat the bad cookies
Fortunately, blocking those cookies is easy with most of the browsers. In some very rare cases not accepting these external cookies could affect the navigation experience (that’s what they say), but I’ve never had any problem. An easy step-by-step guide for Firefox can be found on the Firefox Help, with nice screenshots and everything. For Google Chrome/Chromium, it’s not so well explained on the official Chrome Help (it’s hidden in the “Block cookies by default” section), but it’s just going to Preferences > Under the Hood in the left panel > Content Settings button on Privacy section > Check Block third-party cookies from being set.
And that’s all, Folks. If you research a bit you will find that there are plug-ins and extensions to improve even more your privacy regarding to cookies, but this is a good starting point.