Google introduced a new search feature that allows you to search your hard disk (not the Internet) and so that you can search your hard disk from other computers (let's say you search your work computer from home) the disk's index and the indexed files are stored on Google's servers, so the files can be accessed even when that other computer is turned off.
Some people think this might be a privacy concern:
http://www.eff.org/news/archives/2006_02.php#004400
What do you think?