Actually now thinking about it, hopefully if they are not storing IP(or cookie etc)at any point of time, even temporarily, two searches will not show relationsh

Actually now thinking about it, hopefully if they are not storing IP(or cookie etc)at any point of time, even temporarily, two searches will not show relationship with each other. But I can imagine the benefits of keeping track of all searches done by one user. It can definitely be used to improve the search engine itself.