It's that easy to buy ads that track your location

A study shows how easy it is for anyone to buy ads that access the location and use of apps on the phone.

In the computer we have the famous 'cookies' that know practically all of us, but it is in our mobile devices where a reef of information is larger and more valuable. These devices are always with us, and we use them much more personally, so the data for advertisers is much more juicy. Starting with the GPS of our phone.

A team of researchers from the University of Washington have found a way to track the location of a person and the use made of the applications by publishing ads in the latter.

To demonstrate how this information is obtained, they bought ads on Android terminals based on the geographical position of the devices in specific apps, checking which target audience fits the parameters. They used ten apps, such as Imgur or Grindr, and acquired the ads through ad buying networks available to any mortal.

The result: they managed to find out the location of the user with an error margin of 8 meters through the advertising space hired, being able to know specific places where they have been with only ten minutes of delay with respect to the arrival of the user. The goal has to stay about four minutes before the ad is published, so no red dots appear on the section drawn with a dashed line in the bottom image.


It's that easy to buy ads that track your location in your apps | Agencies
The report argues that taking advantage of this possibility in a malicious way is within the reach of any person, after disbursing an important amount of money. Specifically about 900 euros, since advertising in the mobile environment is more expensive than other online ads.

You can use these placement ads to track business meetings, for example. Or use this privacy gap for dating applications: the authors point out the use for jealous people who suspect the adventures of their partners.

It is also easy to know the list of installed apps as soon as you hire the space, which can give valuable information about that person's interests.

How do you get to know the person? It is done by tracking the mobile advertising ID, which should be secret, but which the authors claim is easy to discover because these numbers sometimes circulate unencrypted and can also be obtained through the detection of Wi-Fi networks.

For users it is difficult to take action on the matter, so the signatories of the document call on the advertising networks to change the identifiers frequently and to improve the detection systems of malicious mobile advertising buyers.