Look here, a really nice simple explanation on how Google search works and a very little but strong message at the end on the potential privacy impacts.
Google auto-complete helps your prejudice
Saw this post by Danah Boyd on how search engine algorithms can produce “false positives” in suggestions from auto complete. An interesting thought, but a bit slim on facts. I wonder how much searching it takes to link names or terms together.
It is still interesting to think that the search engine algorithms, in their endless strive to optimize our quest for all, really just narrows the internet down to what we already liked and thought we knew. That they, in that way confirms our world view, whatever it may be.