Facebook

If you have Location Services enabled on your phone, Facebook may use information about where you are to show you ads from advertisers who want to reach people who've recently been near that location.

To stop seeing ads based on where you are, you can turn off Location Services in your phone's Settings menu.

Keep in mind that while you have Location Services turned off, you won’t be able to check-in, add location to your posts on Facebook or use some other Facebook features that rely on location info from your device.

Note: Facebook also uses information from your account to decide which ads to show you, including the location you include on your profile, your age, gender and the devices you use to access Facebook.