DoudouLinux DoudouLinux

The computer they prefer!

DoudouLinux DoudouLinux

The computer they prefer!

The site's languages [ar] [cs] [de] [en] [es] [fa] [fr] [it] [ms] [nl] [pt] [pt_br] [ro] [ru] [sr] [sr@latin] [th] [uk] [vi] [zh]

> English > Documentation > Advanced tools > Preserving user privacy

Preserving user privacy

June 2013 — last update October 2013

All the versions of this article: [čeština] [English] [français] [русский]

DoudouLinux believes user privacy is essential to aspire to freedom, reduce discrimination and to keep doing what seems best for you, but not necessarily for some companies or groups of people with different motivations. Because we love our children, we do not want them to be controlled in any way by people who would know too much about them and would then be tempted to influence their desires and thoughts for their own self-interest. DoudouLinux is designed by parents who have understood that it is better to keep our children away from third-parties influence and we are convinced that you will agree with this important concern. With the generalized invasion of technology in our lives, the truth is that today many third-parties can gain this influence to serve their own interests, instead of enriching our children thanks to the incredible potential of information technology.

That said, as DoudouLinux can reach the Internet, selecting the best software for DoudouLinux, meticulously taking care of contents is not enough because we do not control what children will get from the Internet. Internet is a kind of fully opened door for people that you do not know and cannot know: you can get the best as you can get the worst. We then have to provide tools to prevent children getting undesirable things from the Internet. This is why DoudouLinux is shipped with built-in Parental controls. Indeed since version 2.0, DoudouLinux does more than just filtering web pages based on their content, DoudouLinux also does its best to preserve user privacy on the Internet. Because we do not want third-parties to know who our children are, what they like, what they are doing, what they read, what they watch, etc., then adapt the content they show our children on the Internet to take advantage of them.

Unfortunately, nowadays, even if you do not have any account on any website, online privacy is not guaranteed [1]. Using a search engine like Google, Yahoo, Bing, Yandex or Baidu is just starting to give them information about you – because they know what you are interested in. Moreover many websites are including in their pages tracking code also called bugs that allow the website or its affiliates to know everything you are doing on their site. They can even know where you are clicking on the page. If the affiliate is a very large company like Google or Facebook, they can nearly follow you everywhere on the web because most of large audience sites are using their services [2]. So, imagine if your phone, your TV, your car, your fridge, etc., are also tracked by these companies… This is going to occur in a very near future!

What DoudouLinux does for user privacy

So to us, user privacy is worth much more than advertisement because people are worth much more than companies. Of course our children are worth even more in the eyes of their parents. This is why we have included tools to preserve user privacy as much as we can. First of all, we have changed the default search engine for the web browser Epiphany and selected DuckDuckGo as a replacement for Google, which was the default search engine of Epiphany. We have also activated in DoudouLinux three kinds of tools to keep children as far as possible from third-party influence:

  • A popup blocker prevents the automatic appearance of advertisement windows. It works by detecting that a window is being opened by the page instead of the user.
  • An advertisement blocker (AdBlock) removes ads in web pages. It works using blacklists of well-known advertisement sources.
  • A tracking code blocker disables code in web pages that is sending information to third-parties about what the user is currently doing or has recently done. It also works using blacklists of well-known tracking code providers.

The two first tools, by removing useless information and entertainment, should also help children better focus on what they initially wanted to read or see. One of the issues with Internet for children is that they can easily spend hours because every page is giving the desire to visit another page, endlessly; just like the cartoon TV channels.

So now let’s see the details.

Why DuckDuckGo

DuckDuckGo is not a well known search engine yet, but it has a better policy than the most popular search engines:

  • They do not record the history of what people are searching for.
  • They do not send that to third-parties either.
  • They allow the user to refuse advertisement in search results, what we have activated in DoudouLinux [3].
  • They do not customize search results people by people, which is also known as the filtering bubble [4].

We believe advertisement is not what people should expect from a search engine, this is why we were looking for a search engine in which ads can be removed and whose search results are not influenced by secret commercial contracts. We want the most relevant information, not the offer from the companies that can pay more than their competitors. We also believe the most relevant information does not depend on who the people requesting are. For these reasons, we do not want either a search engine that collects information about people then resells it in any form to any organization without our explicit consent and without explaining what they really do with it. We want a search engine that just gives the same information whoever the people asking.


  • If you wonder where is the search box in Epiphany, the DoudouLinux web browser, well, it is simply the address bar. Instead of typing the full address of a website, just type your query!
  • DuckDuckGo is currently earning money thanks to affiliates and we must confess we have signed an agreement with them to set DuckDuckGo as the default search engine. Although this agreement is planning incomes for our project according to the monthly visit number, as we have disabled DuckDuckGo advertisements and told them we would do, the income rate should be very near zero for our project!

Our blocking tools

In DoudouLinux, the web browser Epiphany is set by default with its own popup blocker and its own AdBlock extension both activated. Although AdBlock comes with a default blacklist, we feed it too with blacklists designed for the well-known Firefox extension AdBlock Plus and that are even customized for various languages [5]. If a web page is trying to load advertisement, AdBlock prevents the operation and replaces the result with empty content. The page is displayed, but without ads. Goodbye blinking images, children will focus on the real web page content and will not be tempted to loose their time on websites of affiliates.

Additionally, to block tracking code, as Epiphany has no dedicated extension, we decided to operate at the system level. Our web content filtering tool, DansGuardian, can use blacklists of websites spreading tracking code and block access to them, just like it would block access to well-known unsavory websites. We have then added a special blacklist to DansGuardian that contains references of tracking code providers only. When a web page is trying to download and execute such code, DansGuardian is instead returning an error message to the page so that it cannot execute anything. As a result, even if you use another web browser, these codes will still be inhibited! Our blacklist comes from another well-known Firefox extension, Ghostery.

How to tune user privacy

If for any reason you do not feel happy with our choices, you can bypass or modify our settings in a more or less easy way:

  • To allow popup windows, you need to edit Epiphany preferences. Click on the entry Preferences in the menu Edition and select the tab Privacy. Toggle the check box Allow popup windows.
  • To disable ads blocking, you need to edit Epiphany preferences too. Click on the entry Extensions in the menu Tools. This opens a window in which you can select or unselect extensions. Just unselect the extension AdBlock.
  • To allow or block given images or animations in a web page, you need to edit Epiphany preferences again. Click on the entry AdBlock editor in the menu Tools. This opens a window in which you can add or remove entries for the white and the black list separately. It consists of search patterns (regular expressions) to determine whether the path of an image or animation is probably advertisement or not.
  • To change of default search engine, you need to edit the file /usr/share/gconf/defaults/10_epiphany-browser-data and change the value of /apps/epiphany/general/url_search. Administrative rights are required.
  • To allow or block tracking code in a web page, you need to edit the files in /etc/dansguardian/lists/blacklists/nospying/ then restart DansGuardian. Administrative rights are required.
  • To disable tracking code blocking, you need to edit the file /etc/dansguardian/lists/bannedurllist, comment the lines containing /etc/dansguardian/lists/blacklists/nospying/ then restart DansGuardian. Administrative rights are required.

How blacklists are updated

Static blacklists may be efficient enough during weeks or months, but not years because the web is moving fast. Our lists are contained in two separate packages called dansguardian-nospying and epiphany-adblock-lists. These packages are updated several times per year. You can then update them to get newer versions of our lists. Alternatively, it is possible to manually update the lists using the update script that each package is providing. These scripts fetch the lists of interest from the Internet then turn them into our blacklists.


[1] You may think you are not identifiable as long as you have not authenticated on any website, but this is incorrect. Computers have a unique address on the Internet, the IP address, that is often always the same: some people know exactly who is behind which address. Moreover your web browser has a very particular fingerprint that can be used to precisely identify you.

[2] Google is using its website tool Google Analytics and its advertisement selling service Google AdSense to spread tracking code on the web while Facebook is using its button Like.

[3] We believe ads in search results are not enough highlighted as being such (if not discreetly mixed with results), in order to fool users. Obviously children have even less chance to understand the trick.

[4] The filtering bubble is a technique used at least by Google to present users search results that are said to be better corresponding to the people that Google think you are. This tends to show users what they like and agree with, instead of showing them the diversity – which means search results are not objective. This is also an issue if people are not what Google think they are or if several people share the same Internet access equipment.

[5] Our blacklists are downloaded from then converted into Epiphany AdBlock rules.

identica logo facebook logo google+ logo

Geographical location of visitors

DoudouLinux logo Debian logo TSPU logo Genesi logo Gandi logo Hosting Extreme logo Linux Jobs Reviewed by I love Free Software

Creative Commons Copyright © team - All texts from this site are published under the license Creative Commons BY-SA

SPIP | template | Site Map| Follow-up of the site's activity RSS 2.0