Background

Every day, the number of apps, social networks and digital helpers grows. This includes, for example, map and navigation services or purchasing aids. As their use grows, so does the amount of data that will be collected, stored, processed and passed on.
Many people use digital media and devices now as a matter of course. Children and young people grow up with them and cannot imagine life without their devices. But for young people it is not easy to keep an eye on where data is produced in daily use and what is actually happening with it.
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The information that people deliberately share on the Internet or while using apps is usually only a fraction of the data that is actually produced and processed. That’s because the real “data flow” is to a large extent hidden from view. The following example of posting a photo to share will illuminate this.
What does a photo reveal?
A digital image that is photographed with a smartphone and posted on a social networking site provides a set of information:
when the photo file was created and modified.
with which camera or device the photo was taken (manufacturer and model).
where the photo was taken (geotagging).
where the local file is stored.
who has posted the photo.
who viewed or clicked on it in the social network.
who liked the photo, commented on it or shared it.
the interactions that followed the post.
who is pictured in the photo (tagging).
be directly connected to a user.
be associated with a specific person.
be connected to other users.
leave invisible traces online (interests, location, etc.)
So, whoever posts a photo is revealing a lot – much more than is apparent at first glance. And since much of the data is stored, not only the visible data but the invisible stuff too, there are traces left all over the Internet.
Data is particularly valuable
Services are never free – the digital world is no exception. Many online services appear free at first glance, because you don’t have to pay any money for them. Usually, one can only use them by exchanging a particularly valuable “currency”: our personal data.

Personal data provides information about interests, networks, habits and behavioral patterns of users. This information is of great interest for many different stakeholders – operators of online services, advertisers or authorities – and is sometimes even the business model basis for suppliers of digital content and applications. Users often unknowingly grant their consent for the collection, use and transfer of such personal data through the use of apps or online services.
Read more in the "Data privacy" dossier