The nonprofit group US Consumer Watchdog has asked that Google give users of its search engine the ability to 'opt out' of leaving personal data, such as IP addresses, on Google's servers.

"Many people don't understand that the kind of unnoticed conversations that are going on between them and [Google's servers]," said John Simpson, policy advocate at Consumer Watchdog. "Some of that can provide a useful, helpful service to the user, but people need to know what they're providing and made informed judgements about whether they want to or not."

Search vendors have of late moved in varying degrees to assuage user privacy concerns, albeit not to the degree groups like Consumer Watchdog would prefer.

Yahoo recently said it will anonymise most personal data it collects after three months; in September, Google said it would keep such information for nine months, halving its previous policy of 18 months. Microsoft, which now retains the data for 18 months, said recently it would drop that to six months if other search vendors agree.

Consumer Watchdog is targeting Google because the company is such a dominant player in internet search, Simpson said. "It's really the opportunity for them to become the gold standard for privacy on the internet. If they can be made to see the light, then others will fall into line too."

Simpson said he recently became aware that Ask.com provides a service called 'AskEraser', which allows site users to scrub their personal information from the company's systems.

"That's what prompted us to say [to Google], if these guys can do it, why can't you?" Simpson said.

Consumer Watchdog is also asking Google chairman and CEO Eric Schmidt for an in-person meeting to discuss their request.

"I'm very optimistic that he's sincere about listening to people's concerns," Simpson said. "I fully expect we'll have a meeting at some point."