179 lines
5.5 KiB
HTML
179 lines
5.5 KiB
HTML
<style type="text/css">
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.box { border: 1px black solid; padding: 10px; }
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#toc span { font-size: 150%; }
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.pseudo-link { color: blue; text-decoration: underline; }
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</style>
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<!--
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<div id="toc">
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<span>Contents</span>
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<ol>
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<li><a href=""></a></li>
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<li><a href=""></a></li>
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<li><a href=""></a></li>
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</ol>
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</div>
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-->
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<h1>Privacy protection</h1>
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<p>
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Have you ever wondered why so many web sites offer various services for
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<q>free</q>? Consider social networks. They let you stay in touch with
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friends, share photos, chat, recommend stuff, etc. Even if you are not
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involved in a social network, you are probably using one of those cool
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services around there such as a web feedreader, photo albums, online
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documents, and so on.
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</p>
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<p>
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Are they giving you "free" services? This depends on your definition of
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<q>free</q>. Using them doesn't actually cost you money <em>directly</em>.
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However, these companies do need money to operate. Their source of
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revenue is derived mostly by advertisers and the more
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information these companies have (tastes, thoughts, locations, relations, …),
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the more they can profit from selling it. Yes, that's right: they sell
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<em>your</em> information.
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</p>
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<p>
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Too much paranoia? Maybe. However, let's try a test. Visit the link below
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(it will redirect to doubleclick.net; it will work better if you visit it
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with a browser/computer used only by yourself with no blockers):
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<p>
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<p>
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<a href="http://www.google.com/ads/preferences/"
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rel="external">http://www.google.com/ads/preferences/</a>
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</p>
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<p>
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It probably guessed your demographic information and/or interests. How do
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they know? They track your internet usage by means of an <q>HTTP cookie</q>,
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which is a small file that some websites leave on your computer when you
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visit them. While it is not a big issue <i>per se</i> (they can be used to,
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for example, save your preferences for a website), they can also be used to
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collect information about you, as shown above.
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</p>
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<p>
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A cool and informative visualization of the tracking process can be seen
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here: <a href="http://collusion.toolness.org/"
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rel="external">http://collusion.toolness.org/</a>
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</p>
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<h2>Tracking methods</h2>
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<p>
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So, it would seem HTTP cookies (as just seen) are the problem. No, it is
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(was?) the most widely used/known method. There are various other
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techinques:
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</p>
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<dl>
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<dt>Local Shared Objects</dt>
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<dd>Like standard cookies, but done with Adobe Flash. Check the <a
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href="http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager06.html"
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rel="external">Website Privacy Settings panel</a>.</dd>
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<dt>Zombie cookies</dt>
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<dd>Yet another cookie type. This one's particular, though. It will be
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recreated even if the user has deleted it. Actually, it's not just a
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single cookie, like the HTTP or flash types. Other storage mechanisms
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will additionally be used (e.g., <q>HTML5 Storage</q>, <q>Silverlight
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Isolated Storage</q>, <q>Web cache|history</q>, etc. and if the user
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fails at removing them, they will repopulate the data storage. Read
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more here: <a href="http://en.wikipedia.org/wiki/Zombie_cookie"
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rel="external">http://en.wikipedia.org/wiki/Zombie_cookie</a>.</dd>
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<dt>Web bugs</dt>
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<dd>A small or invisible object (like a 1x1 pixel image) is put into a web
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site or e-mail message which is loaded from a third party. Read the <a
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href="http://w2.eff.org/Privacy/Marketing/web_bug.html"
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rel="external">Web Bug FAQ</a></dd>
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<dt>Browser fingerprinting</dt>
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<dd>Your browser can send information that makes could make your system
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uniquely identifiable. See <a href="http://panopticlick.eff.org/"
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rel="external">http://panopticlick.eff.org/</a></dd>
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<dt>XXX More?? XXX</dt>
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<dd>XXX</dd>
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<dt></dt>
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<dd></dd>
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<dt></dt>
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<dd></dd>
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-->
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</dl>
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<p>
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Even if you don't care about online privacy, you should be aware of the fact
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that some of the above techiques can be used to impersonate you. See, for
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instance, an article about <a
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href="http://en.wikipedia.org/wiki/HTTP_cookie#Cookie_theft_and_session_hijacking"
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rel="external">Cookie theft and session hijacking</a>.
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</p>
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<p>
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So far we have seen some of the hidden risks to your online privacy that
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don't require you to do something in particular, just that you browse the internet.
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There are also various activities that are based on the information you
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explicitly give (though, of course, the methods discussed above still
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apply): search engines and social networks.
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</p>
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<h2>Search engines</h2>
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<p>
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Every time you submit a request to a search engine, they will log it and
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associate it with you. XXX expand XXX. Alternatives: <a
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href="http://duckduckgo.com/">http://duckduckgo.com/</a>, ...
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</p>
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<h2>Social networks</h2>
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<p>
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XXX expand XXX
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</p>
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delete EXIF information
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<h2>Protect your privacy</h2>
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<p>
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So, how to protect your privacy on-line? Some useful suggestions:
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</p>
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<ul>
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<li>Install an ad- or script-blocker and/or a filtering web-proxy:
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<a href="https://addons.mozilla.org/en-US/firefox/addon/noscript/"
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rel="external">NoScript</a> and <a
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href="https://addons.mozilla.org/en-US/firefox/addon/betterprivacy/"
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rel="external">BetterPrivacy</a> (for Firefox), <a
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href="http://www.privoxy.org/" rel="external">Privoxy</a>.
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</li>
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<li>
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Turn off HTML in your mail reader (for web bugs).
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</li>
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</ul>
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<h2>Resources</h2>
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<ul>
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<li><a
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href="http://www.eff.org/wp/effs-top-12-ways-protect-your-online-privacy"
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rel="external">EFF's Top 12 Ways to Protect Your Online Privacy</a>
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</li>
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</ul>
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<div id="rcs_tag">$Id: privacy_protection.html,v 1.3 2011/11/28 16:58:03 jbaber Exp $</div>
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