This mobile phone was used to call the personal number of William Binney, a former technical director of the U.S. National Security Agency who quit in protest in 2001 and later became one of the first whistleblowers on illegal NSA programmes. He must be considered to be what the intelligence agencies call “cast iron” – an internal term to identify targets that are so important that every bit of data personally connected to them has to be recorded and saved forever.

Since it was used to call Binney, we must also assume that the number +49 174 276 6483 is now also under direct surveillance.

But as we know it's not only select individuals that are under surveillance. Everyone is. One of the oldest such bulk monitoring programmes is the collection of call data: Who called who, from where, and for how long. This is the metadata that each phone call generates. It is being used to draw a graph that illustrates personal relationships, and that is being done over at least three hops. It works like this:

Let's say someone is – for whatever reason – attracting the interest of the intelligence services. The first thing that they will do to find out more is to map out a social graph. Such a graph includes not only phone calls, but also email, chat, and social media contacts. As a first step all direct contacts of the target person (in the centre of the graph) are being pulled up. (fig. 1)

The second hop maps all other connections of the direct contacts. (fig. 2)

It doesn’t stop there: The third hop then identifies any connections of hop 2 contacts. (fig. 3)

These three drawings are simplified for the sake of clarity and show only a small fraction of the typical number of phone and email contacts. People usually have a considerably greater number of direct connections. And, as shown, it's not just your own contacts. By extending the reach to the contacts of contacts of contacts, the amount of people under examination increases exponentially. An enormous number of uninvolved bystanders are being drawn into intensified surveillance. Estimates for the average amount of hop 3 contacts range from 5 to 30 million.

So the connections that you made with the phone in your own pocket are also very likely already part of various databases. If at any point in the future someone becomes a person of interest, and you have been even remotely connected to that person, the stored metadata will be used to draw a map of your social contacts. This also works retrospectively, going back many years.

We are powerless against this sort of surveillance. And an agenda like this is not compatible with a democratic system. One of the most insidious problems is the so-called “chilling effect”. Once you know that these systems exist, you inadvertently restrict yourself. You stop using certain words and you don’t talk freely any more.

A subtle and rarely discussed side-effect of the ongoing revelations is that they make the “chilling effect” ever more effective. This self-censorship is automatic and takes effect before you even notice. Calls for increased use of encryption don’t help here. The only thing that you can do is consciously decide not to let yourself be restricted in your actions.

Well, here’s an opportunity. The phone with the number +49 174 276 6483 is a first degree contact in William Binney's social graph. By calling this phone from your own device you add yourself directly to it and become hop 2.

Why should you do that, you might ask. It’s true, you’ll be associated with Binney. As will be all of your personal contacts. But what’s at stake here is something that is a lot more important than the potential ramifications of a data trail.

Do you really want to live a life where you shy away from completely normal, legal things, like calling a mobile phone?