According to ChannelWeb, Microsoft has said that it will further reduce the amount of time that search activity data is retained, as long as their competitors - Google and Yahoo! - do the same.

This relates to demands by the European Commission privacy panel that search engines should not retain information on users' search activity, which are currently held for 18 months. Microsoft has said that they would be prepared to reduce this time period to 6 months to meet the demands for search anonymisation. Google curently holds data for 9 months, and Yahoo! for 13 months. Whether the other search engines will agree to this shorter period remains to be seen.

The main search engines retain information on users' online search behaviour in order to target advertising and, as persoanlised search becomes more active, to retain historical data to help imporve search results. However, privacy critics say that keeping these records raise concerns about identity and activity patterns, which should be protected. Most searchers are probably unaware that their data is being collected in this way and if they choose to use persoanlised search, they are agreeing that their historical data will be kept for a period.