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Search Engines and Online Privacy

How many times did you use a search engine last week? No idea? The search engine company will know, although they probably won’t tell you. They will know a lot more than that, too.

Your Information in Their Hands

Each time you search online, you are handing out information about yourself. Search engines give information to you, but you also give information to them.

The search engine company you use will normally keep a record of the following types of information:

How Search Engines Keep Track of You

To keep track of you, search engines use a combination of cookies and IP addresses.

Search Engines and IP Addresses

Your IP address is a sequence of digits which identifies your internet session. It is assigned by your internet service provider, who will keep a record of which IP addresses are assigned to which subscriber.

Search engines and other websites you visit will not be able to match an IP address to a particular subscriber, and so will not be able to identify you directly, unless, of course, you use the search engine which is included as part of many internet service providers’ packages. You can find out your current IP address by going to

Search Engines and Cookies

Almost all search engine companies will try to attach a cookie to the computer of everyone using their service. The cookie will enable the company to identify your computer each time you use the search engine.

Even though the search engine company won’t know your name, its cookie will tell it the IP address that has been assigned to your computer. This in turn will allow the company to tie together all your search terms from that session as well as the websites you have visited as a result of those searches.

Of course, if you have an account with a search engine company and are logged into that account when you make your searches, the company will be able to match your searches to your name and to any other personal information you have given them.

The AOL Data Privacy Scandal

There was a minor scandal in 2006 when AOL made public a tiny proportion of the records of its associated search engine, which is based on Google. It revealed more than 20 million search queries made by 658,000 unnamed individuals over three months.

Most of the media discussion at the time was about AOL’s decision to make the information public, and the consequences for any identifiable victims. Less was said about the fact that most AOL subscribers would not have been aware that such information had been collected in the first place.

Try Out the AOL Database

At the time of writing, the AOL database was still available. Try it for yourself:

  1. go to;
  2. click on ‘randomizer’;
  3. click on a user ID to find out which other terms that user has searched for, and which websites he or she visited.

Someone’s Search History

Look at the following search terms, all from the same American AOL subscriber. See what you can deduce about this person:

For more examples, see this article on Incidentally, the leaked database has even become the source material for a play.

Identifying Users of Search Engines

A handful of odd internet sessions and searches won’t disclose much about you. As the AOL case made clear, however, several months’ worth of data can sometimes reveal more than enough to identify an internet user, even if no names were attached to the publicly available data.

As it happens, AOL did possess most of the names to go with the data, not to mention email addresses, postal addresses, and credit card details.


There are four main ways to prevent any search engine company assembling information about your searching activity:

Delete Their Cookies

Deleting cookies is very easy – see our Internet Privacy page for details.

Change Your IP Address

Many users with domestic broadband connections keep their internet sessions going for weeks, months, or even years at a time. During a session, the IP address will normally remain unchanged. Every search made during each session can be related to that session’s single IP address.

So change your IP address from time to time. Break the connection by simply switching off your broadband router for a while, and you will normally be allocated a different IP address the next time you switch it back on.

Search Anonymously

The best way to search anonymously is to use one of these search engines:

None of these three record their users’ data. Startpage and IXquick are two versions of the same search engine, with minor differences. Duck Duck Go, despite its rather silly name, offers an extra privacy feature. Unlike other search engines, it does not send your search terms to the websites you visit as the result of a search.

All three allow the use of a secure and encrypted connection (https rather than http), which prevents the monitoring of data that passes between the user’s computer and the search engine’s servers, albeit at the cost of a slightly longer waiting time.

Duck Duck Go provides these two amusing and very informative graphics that illustrate what happens to naïve web users who allow search engines to build a profile of their interests:

Disguise Your IP Address

You can also search anonymously by disguising your IP address. Some websites, known as ‘anonymizers’, offer an encryption service that allows you to surf while keeping your IP address hidden from the websites you visit, which include, of course, search engines’ websites:

There are some companies that offer similar services but which require you to install their software on your computer. They charge a monthly fee, but they usually allow a free trial period:

Corrupt Their Records

The search terms you use will paint an accurate picture of you only if those search terms are authentic. So add some background noise: from time to time, search using words and phrases that don’t have any relevance to your life or your interests. You can do this automatically by using Track Me Not, an extension for the Firefox and Chrome web browsers.

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