Facebook keeps tabs on you from its site….

Assembling your profile: This is where your Facebook presence begins.

• When you create an account, Facebook asks for your name and birthdate, along with either a phone number or e-mail.
• Then there’s all the information you give Facebook as you fill out your profile, potentially including schools, current and past occupations, relationship status, hometown and current city, as well as your physical address, birth name, web site and other social links.
• All of this forms the core of the profile Facebook uses to serve you ads. It’s why you see offers for clever T-shirts based on your college or job.

Following what you do on Facebook: The company has near-total awareness of every move you make on its website or in its apps, including:

• When you log in, how long you spend online and where you are logging in from — hence it can welcome you to new cities and suggest places to visit and eat (and also serve up local ads).
• Places you check in.
• The pages, accounts, and hashtags you connect with on Facebook — and not just who you are connected with, but how often you interact and for how long.
• Your contacts, if you choose to upload your phone book or call history.
• Things you buy directly from or through Facebook, but also things you may not think about, like the metadata from photos you upload.
• Your friends can tag you in posts and photos, which gives Facebook additional information. (You can choose to have this displayed publicly or not via privacy settings.)….

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