A recent study by CNET shows that, among the top five search engines, Ask.com is the one paying the most attention to privacy concerns.

Many of the top online search engines retain their search data for long periods of time, increasing the risk that the data could be used to link online search behaviour to individuals. Some of the search engines also use this collection of data in order to specifically target ads toward the end user based on searches and search behaviour.

While many people don’t see a down side to having a search history of their searches available, it’s becoming a growing concern as more companies are using data mining techniques to attempt to build profiles of individuals. These profiles are often used for employment or credit purposes, but such data could be used by everyone from attorneys in civil suits to nosy neighbors if it’s not kept well-guarded.

Last year, AOL released the data of 650,000 users’ searches, partially anonymised, but even anonymous search data contains  some disturbing revelations and could be used to tie people to search habits and behavioural traits — especially if one indulges in a vanity search. Then, it becomes an easy matter to tie a person to a list of search terms.  While many people search for the necessities of life, some search randomly or even search based on terms found in online news stories, blissfully unaware that such terms might then be used to paint a picture of their life or interests.

Many younger people are suddenly discovering what a bad idea it was to post personal information on sites like MySpace when out looking for a job later on in life, but search data can show an even more intimate snapshot into a person’s life. Left unguarded, companies might begin using such information to build a profile of employable candidates or employment risks.

Public outcry has been enough to make some companies think twice about how secure their search data is, but until set rules are passed on how much data may be accumulated, and what may be done with it, companies are somewhat free to do what  they please with their search data. It is wise to know how your favourite search engine ranks in terms of its commitment to your privacy.