Ask.com on Monday became the first major search engine to let users decide whether it can keep records of their queries in a move hailed by privacy watchdogs.
The new Ask.com function could protect people as technology that tracks digital footprints becomes increasingly sophisticated, allowing marketers to mine a wealth of information to tailor advertising and promotions with ever-greater precision, privacy advocates said.
They said they hoped the effort by Ask.com -- the fifth-largest U.S.-based search engine -- would spur others to follow suit.
"It's good when companies innovate," said Marc Rotenberg, executive director of the Electronic Privacy Information Center in Washington. The center and other groups have pressed Congress for a comprehensive federal privacy law to protect people online.
"Over the long term, we still need appropriate legislative safeguards," Rotenberg said.
Ask.com's privacy control, called AskEraser, deletes all searches within hours of a user turning the feature on. A link to AskEraser is in the upper right corner of the home page and on search result pages.
"Having the control to use it or not goes a long way toward making consumers feel comfortable," said Doug Leeds, senior vice president of Oakland-based Ask.com, which is owned by IAC/InterActiveCorp.
Nearly all search engines record queries, along with the identity of the computer that submitted each query, for as long as 18 months. Collecting and storing this data helps them generate better search results and more relevant advertising, according to the companies, and aids in the fight against spam and fraud.
But search data can contain sensitive information -- medical conditions, political beliefs, financial dealings -- that could put people at risk if made public.
"A lot of information is recorded about people online that people don't have control over," said Danny Sullivan, editor in chief of Search Engine Land, an online trade publication. "It's time for us to get a better idea of what private information companies are keeping on us and what kind of control we have over it."
In response to public pressure, major search engines issued new policies, with Google Inc. and Microsoft Corp., for instance, saying they would make search log data anonymous after 18 months. The Dutch metasearch engine Lxquick.com -- which simultaneously searches multiple other engines -- recently began making searches anonymous within 48 hours and deletes the information within 14 days, Chief Executive Robert Beens said.
People concerned about privacy have alternatives. Anonymizer services, for instance, that can mask online activities are available on the Web.
AOL ignited a furor last year when it inadvertently released more than 20 million queries made by 658,000 users. Scrutiny of search engine privacy practices increased when Google refused to comply with a Justice Department subpoena seeking consumer search data.
In Washington, lawmakers and regulators are examining the privacy implications of Google's proposed $3.1-billion purchase of Internet advertising broker DoubleClick Inc. because both companies track and store so much consumer information.
This month, after nearly 700,000 people joined an online protest, social networking website Facebook.com began allowing users to turn off a feature that tracked what they purchased online and published the information for friends to see.
"If people understand the privacy risk to them, they speak up," said Ari Schwartz, deputy director of the Center for Democracy and Technology in Washington.
"People are paying more attention to these issues."