system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is the big deal about Google's privacy? Is it safe/smart to use?
gpt
Google provides a huge number of services for free. In order to do this, they make money by showing relevant ads when you search, check gmail, watch YouTube, etc. People are more likely to click ads relevant to them, so Google collects information about you when you use their services. For example, they might use your IP address or phone's GPS radio to figure out where you are, then show you ads for local businesses.

In fact, if you have an android phone and opt-in to Google Now, they will try to learn all sorts of things like where you work, where you live, what you search for, what sports teams you follow, what stocks you own, what flights you are about to take, and all sorts of things. They use this information to show you relevant information in Google Now before you ask for it, like automatically showing scores for a local sports team or telling you what gate your flight will be departing from.

People freak out about all this because it feels like a company knows way too much about them. While it's true companies like Google or Facebook collect data about everyone who uses their services, there isn't a human being sitting down and reading it. All this information is used in aggregate to make Google more money by providing you with more relevant information.

This isn't "unsafe" by any means, but if you are paranoid about companies knowing about you, don't use Google, Facebook, Twitter, etc. It's been reported that Google and Facebook never search through people's personal information to look for illegal or suspicious activity. The only way these companies release their information to other people is if law enforcement forces them. Google has publicly stated they are just as concerned with organizations like the NSA snooping on their data, and have started encrypting more and more of their services.