Internet users are taking a fresh look at "privacy" search engines that do not store data or track online activity, in light of the flap over US government surveillance.

While Google's market share has not seen a noticeable dent, privacy search engines like US-based DuckDuckGo and European-based Ixquick have seen jumps in traffic from users seeking to limit their online tracks.

"I think people are seeking out privacy alternatives," said Gabriel Weinberg, founder of DuckDuckGo, an engine created in 2007, which does not store IP addresses or create profiles of users.

The stored data has become a concern following revelations of a massive surveillance program run by the secretive National Security Agency, with access to data from Google, Yahoo! and other Internet firms.

US officials say the information gathered is vital in the fight against global terrorism.

The same data and profiles can be used by the search engine to deliver ads and sold to outside marketers as well.

"What people type in their search engines is their most personal things," Weinberg said. "It's a little creepy that a search engine can know so much about you."

DuckDuckGo had been growing slowly in recent years, but its traffic charts showed a surge after the first news broke June 6 of the government's PRISM surveillance program. By June 20, traffic had hit nearly three million queries, double the level of a year earlier.

More than half of DuckDuckGo traffic comes from outside the United States, Weinberg said.

"This NSA story played into the trend of people's fears" about online tracking, said Weinberg.

Weinberg said another factor is that Google results are being gamed by search engine spammers and other companies trying to rank their results higher."

Dutch-based Ixquick, which also uses the name StartPage, said it too has seen a dramatic jump in usage after news of the PRISM data sharing program.

Last week, the two meta-search engines -- which use the results of Google and other search sites and strip out identifying information -- served as many as 3.6 million queries.

"This growth has been sustained, it shows no signs of slowing down," said spokeswoman Katherine Albrecht.

The revelations about PRISM "really have woken people up," she said.

"People had heard the message of privacy but hadn't been able to nail it down to how it relates to them."

The company proclaims it "has never turned over user data to any government entity anywhere on earth" and is "not directly subject to US jurisdiction."

Another search engine, California-based Blekko, allows users to select privacy settings and keeps no data if the user selects "do not track."

"Even if you are not a criminal, you probably make searches that you don't want your minister, boss, or spouse to know about," said Blekko's Greg Lindahl.

Weinberg said DuckDuckGo's model allows it to make money through "keyword" advertising, without stored profiles. So if someone is searching for a "mortgage," they might see ads for banks.

This differs from search engines that track the pages people visit and then deliver related ads, a practice known as "retargeting."

"Retargeting is effective only for a small amount of people, the rest are just annoyed by it," he said.

Danny Sullivan, editor in chief at the specialized website Search Engine Land, said these kinds of search engines were "interesting" but unlikely to have a major market impact.

"It's extremely unlikely in the next three to five years that any player will come along and take a sizeable share away from Google," he said.

A survey of the US market by the research firm comScore showed Google with a 66.5 percent market share, with 13.3 billion search queries in a month, followed by Microsoft (17.3 percent, 3.5 billion) and Yahoo! (12 percent, 2.4 billion).

Sullivan said the news over NSA surveillance "so far doesn't seem to be spooking" the public.

He said Google does not force people to create a profile that can be used to connect with its other services.

"You can go to Google, and you can do a search without being logged in, and you still get very good results," Sullivan said.

"If you do log in and connect to these services, Google blows DuckDuckGo out of the water. When it has access to your calendar and search history, Google can predict your answers before you even ask them."