information you will ever reveal online: your health, mental state, interests, travel locations, fears and shopping habits.
And that is information most people would want to keep private. Unfortunately, your web searches are carefully tracked and saved in databases, where the information can be used for almost anything, including highly targeted advertising and price discrimination based on your data profile.
Nobody understands the long-term impact of this data collection, said Casey Oppenheim, co-founder of Disconnect, a company that helps keep people anonymous online. Imagine that someone has 40 years of your search history. Theres no telling what happens to that data.
Fortunately, Google, Microsofts Bing and smaller companies provide ways to delete a search history or avoid leaving one, even if hiding from those ads can be more difficult.
Google makes it easy to find your personal web history, manage it and even delete it. Just go to http:// google.com/history and log in to your Google account. There, you will see your entire history and can browse it by category. For example, in the last month, Ive done image searches for Gal Gadot (who will play the new Wonder Woman), pointy nail trend and Wayne Rooney hair transplant, plus a few more intelligent things, Im sure.
If you would like this history to go away, click the gear icon in the upper right of the page and choose Settings. Here, you can turn off search history, so Google wont save future searches. You can delete your history from Googles database or just remove specific items from your recent history.
This does not opt you out of ad tracking, however. It just gets rid of a potentially embarrassing or damaging historical record. Google also lets you opt out of targeted and search ads on the web and in Gmail, at http://google.com/settings/ads.
You can turn off and erase your search history on Microsoft Bing at https://www.bing.com/profile/history. Yahoo lets you turn off future search histories but doesnt have a way to delete the old one. Visit http:// search.yahoo.com/preferences/ to turn off your history.
Even with your history turned off, though, you are still sending a lot of personal data when you surf or search from all three, especially if you are logged in to your Google, Microsoft or Yahoo account when you search.
Gabriel Weinberg, chief executive at the alternative search engine DuckDuckGo, says there is a different way, and it can still involve making money from search-related ads.
DuckDuckGo collects no personally identifying information (like your I.P. address) as you search and doesnt save any search history that can be tied to you. But DuckDuckGo still makes money on ads. Its a myth that the search engines need to track to you to make most of their money in web search, Weinberg said. Most of the search ads are based on the queries you type in and have nothing to do with your search history.
DuckDuckGo said its searches more than doubled from 2012 to 2013 to over a billion queries a year. That is tiny compared with Google (100 billion searches a month) or even Bing or Yahoo, but the growth demonstrates a real interest in private searching. Other options include PrivateLee, Qrobe.it and IxQuick, which is based in the Netherlands.
Using DuckDuckGo or another private engine takes a little getting used to. DuckDuckGo doesnt autocomplete search terms, for example, but PrivateLee does. They obviously dont filter results on the basis of your past searches, either. The results may seem a little strange as a result.
If you are partial to Google, Bing or Yahoo as a search engine but want it to be anonymous, try Disconnect Search.
The web version lets you specify Google, Bing, Yahoo, DuckDuckGo or Blekko as your engine, but it searches them without sharing your Internet address or saving a search history.
You can also install Disconnect Search as a plug-in for the Chrome or Firefox browsers, so you dont have to remember to go to the site. There is an Android app available, but none for Apples iOS. Disconnect also offers other privacy tools that block ad tracking in browsers and on iOS.
Disconnect Search isnt perfect. For one thing, it forces all search searches into whatever search engine you have set as your default. So if you are clicking search links on the Yahoo home page, you wont end up in Yahoos search, you will end up in your default.
It also cant handle Google Maps links. If you click a link to a Google Maps location from a website, for example, you will be taken to a search result for that address, rather than the map.
So why do all of this If you have been wondering why eerily specific ads keep showing up on every site you visit, in your email, on Facebook or anywhere else you go online, its because those advertisers do know you that well.
Search companies like Google feed your queries to advertisers, who use them to show you ads related to your interestsand that is just on Googles site.
When you click search result links, the sites you visit can access your search terms and your I.P. address, which can determine the location of the computer you are using. That means those third-party sites also know what you searched for and who you are or at least where your computer lives.
In addition, your search history can create something called a filter bubble. As you build up a history of clicks and queries, Google will start delivering search results tailored to what it thinks you want to see. As a result, your results start to reinforce your worldview or even start to be less accurate, as you see only sites like those you have clicked on before.
For me, the right combination of privacy and search convenience came from making DuckDuckGo the default search engine in my browser. I like its instant search results, which appear above the rest of the results, and its fast and accurate. Ads are clearly marked and often relevant.
While Google does give users some control over their web and search activities and ad tracking, it will always be in that companys best interest to share your information to serve you better ads and to collect as much as they can. That is not necessarily in your best interest.
Privacy matters for many reasons, both tangible and not, and its wise to exercise control when you can.