How Your Phone is used to Spy on You.

In a University of Washington study, titled “Using Ad Targeting for Surveillance on a Budget,” they created a mobile banner ad and a website.

Next, they purchased advertising from companies like Facebook and Google that sell advertising based on the geographical location the ad appears, which apps are used, and which mobile advertising ID is used. (The key to tracking someone is the mobile advertising ID. The value is simply a hash of someone’s email address.)

Once an advertisement is displayed, the researchers received confirmation showing approximately where, when, and on which phone the ad had been shown. This effectively showed them where the person was when they were shown the ad, what app they were using, and other details.

In summary, if someone has your primary email account, they can create advertising specifically targeting you. These ads  can reveal your location and other information about your phone.