Google parent company Alphabet quietly ditched the 'Don’t be evil' motto from its code of conduct in 2015 after a string of stories suggesting the pithy slogan was somewhat undeserved. According to WikiLeaks founder Julian Assange, the company has quietly collected more data than the NSA.
It's a Faustian pact that most of us are happy to make for the rich range of services we receive in return, but the true terms of the deal may not quite match what you thought you had signed up for.
Read on to find out what information that the tech titan has gathered about you, and how you can get it back.
1. Google knows what you’re like
The data Google mines paints a vivid portrait of the person you are. Your age, gender, and interests are predicted by its algorithms with impressive accuracy.
If you fancy a change of personality and being presented a different set of advertisements, you can change your personal data and the personalised ads it's used to form by clicking Manage ad settings in the personal information section of your Google account.
2. Google knows what you’ve said
Every time you speak to Google it records your voice. The company says it collects this data to improve its voice recognition software and only records it when users opt-in.
You can find and delete all the recordings of all your Google voice searches and your Google Now and Google Assistant commands by going to the Voice & Audio area of the My Activity section of your Google account.
3. Google knows who your friends are
Gmail correspondence means your contacts are all logged. Not only does Google know who you've been in touch with, it knows which of them you like best.
Google Contacts keeps a record of who you've interacted with the most, and lets you remove any of the people you no longer want in your life.
4. Google knows what you’ve seen
Google acquired YouTube for $1.65 billion in 2006. What seemed expensive at the time looks a bargain today, and not only for the advertising revenue. The company can also track exactly what you've searched for and watched on the video-sharing service.
You can find a full history of the videos you've searched for, viewed and voted for and update your privacy settings in the YouTube section of your Google Dashboard.
5. Google knows what you search for and it knows where you browse
Google Chrome maintains a bewildering breadth of additional personal information. It knows where you've been, the apps that you've used, your autofill data and your favourite pages. Chrome Sync calculates exactly what that amounts to.
Every site you've ever visited is stored in Google, Chrome and your Android apps. It knows when you search and what you search for, how many searches you've made and your top queries.
It's easy enough to clear your search history, but that doesn't mean it no longer exists. Follow Google's instructions to permanently erase the past and limit the tracks of the future.
6. Google knows almost everything you’ve done with your Android phones
Another of Google's most successful acquisitions was that of mobile operating system Android, which Google bought for an estimated $50 million in 2005. Every Android device ever used is known to Google, and everything that's been done with them.
Your contacts, call logs, messages, voice command, where you've been, your browsing data, and the apps you've downloaded from the Google Play store casts a long and revealing shadow.
You can find out exactly what is known and limit what is tracked using the filter available in the Item view of the My Activity section of your Google account.
7. How to find out exactly what Google knows
Google released a new dashboard feature last June that reveals exactly what it knows about you.
My Activity displays all your search history, the links you've clicked on, the YouTube videos you've watched and the Google Map searches you've made all in one timeline, and lets you expunge all of them as specific items or as entire topics of content.
It also offers the option to determine what data will be associated with your account in the future.
Another setting lets you decide what kind of advertising you receive. Under the Ads Settings section of your Google Account you can review the current commercial offerings based on your existing user information, and choose which type you no longer want to see.
Google also provides a comprehensive Dashboard showing all the personal data collected through your Google account and the devices attached to it, and lets you edit the privacy settings as you see fit.