A European Union privacy panel on Wednesday urged Internet search engine providers like Google Inc., Yahoo and MSN to delete data taken from users after six months.
A report from the EU-funded privacy watchdog recommended the search engines live up to European data protection rules, even though most are based outside the bloc.
While the watchdog has no policy powers, its report could lead to stricter regulations by the EU's executive Commission, which is currently redrafting data-protection rules for the 27-nation bloc.
The report said search engines fall under the rules drawn up in 1995 if their operators collect users' Internet Protocol addresses or gather search-history information by using cookies — small data files installed on surfers' computers to gather insights on usage.
Treating IP addresses — a string of numbers that identifies a computer — as personal information would have implications for how search engines record the data used to understand search patterns and correctly bill online advertisers for the number of times their ad is viewed.
The panel said that information taken from users, such as search logs, should be erased after six months, to better protect the privacy of users and to avoid any possible misuse of the data. Such search histories recorded by the engines can be a boon to advertisers finding out everything from what clothes a user likes to music or movie preferences.
"If personal data are stored, the retention period should be no longer than necessary for the specific purposes of the processing. Therefore, after the end of a search session, personal data could be deleted and continued storage ... needs an adequate justification," the report said.
The panel also slammed the companies for failing to properly inform users on why some information is needed to perform searches on their sites.
Search engines have already gone some way to responding to privacy concerns, led by Google which was the first to cut the time it stored search information to 18 months.
Google's global privacy counsel, Peter Fleischer, told EU lawmakers in January that Google collects IP addresses to give customers a more accurate service because it knows what part of the world a search result comes from and what language the user uses ’ but it was not enough to identify an individual user.
Google says it needs to store search queries and gather information on online activity to improve its search results and to provide advertisers with correct billing information that shows that genuine users are clicking on online ads.