Much like the people who rant about how evil Google is. You guys all act like they're selling your name and social security number to Satan himself.
As a long time Google user (of a LOT of their services), I never feel unsafe or compromised while online. I never have problems with ads or marketing, and have never felt like I was being made a product, as so many seem to think.
Plus, what sort of information are they sharing? My name? The area I live in? The fact I browse for MTG cards online frequently? Who cares? This is all information that is available publicly if you know where to look.
You need to realize that what advertisers are after are a broad generalization of user habits. They have no interest in your specific name or address, they more want categorised data (eg. I'm a white male, 20-24, plays video games, interested in IT industry). THAT is more useful to them than what my dog's name is, or what time I get up every morning.