Google tracks everything so they can put you in filter bubbles.
Basically putting you on specific ads based on interests, location etc.; giving you more and more relevant results (If you have 2 people that used Google as search engine for awhile, even from the same location, to search the same thing, they will have different results), relevant ads..
Yeah, though it is annoying, it doesn't particulary harm anyone in any condition. Though slamming ads in your face is bad enough and I wish I didn't have filter bubbles.
And that's where DuckDuckGo goes to. But I still like Google more because of it being more sleek than DDG.
Though, Google can give the info to the police if anything goes wrong. And so can your doctor, your.. oh wait, your everything. Let's sue the world.