[on_and_off]

Google does indeed use my data in order to personalize search results. I remember being impressed to see that for a query that could have several different meanings, the search engine gave me results centered on my engineering field, which was what I was looking for. I am not that convinced that it blindfolds you to some services or opinions though. So far I have only seen differences in understanding the context of the query, which I don't see as an 'undue bias' but an added value (especially if you read the anecdote about the 'history of aviation' query in this thread).

Some other thoughts on the bubble : http://www.blindfiveyearold.com/the-preference-bubble .