We reproduce below the article opinion recently published in El Diario Vasco by Nicolás Serrano, professor at Tecnun- Engineering School of the University of Navarra, on the protection of our data.

"In the last year there have been quite a few news stories about the use of user data for purposes other than those for which it was intended. One of the most prominent cases has been the sale of Facebook user data information for the Brexit campaign.

Some people are jealous of their privacy, while others consider that it is not so important that what they do publicly is known to companies they do not know. Although they assume that they are providing a useful and usually free service, many wonder what interest companies might have in such data.

We can begin to intuit its value, if we think, for example, of what can happen to us on a train trip of average hour, if the person sitting next to us slyly watches our activity: the news we consult, the emails we answer or how we interact in our social networks. It is clear that, with those minutes of information, the person who has observed us could issue a fairly complete report of what are our tastes, activities and affinities.

Everything that this person could see is accessible day after day for the applications we use, since they are the ones that are processing that data. If the recording of information is not limited to a specific section of a trip, as in the case of the train, and it is something that occurs continuously over time, this information can be crossed with that of the other people with whom we have a relationship or the media with which we interact. Therefore, the information we leave available is very exhaustive.

In addition to the information that the person sitting next to us can see on our computer screen, the different devices that are connected to the Internet, such as the computer, mobile phone, video game console, smart speaker, printer, and even different household appliances or Internet of Things devices, can transmit other less visible data. Examples include geographic location, hours and level of physical or digital activity, the conversations we have or the images we exchange. These are not just rumours circulating on the internet. The police themselves distribute covers for webcams on computers and security experts are the first to have these webcams physically covered.

Therefore, our digital footprint is not limited to the pages we personally write on our website, blog or the messages we post on social networks. There is a digital layer over all our activities that, in addition, have the ability to persist over time on the servers of all companies and organizations that have collected this information. We are dealing with a layer that transmits and can store the activity of all the people and organizations connected to the network.

But what can a computer do with this data? The answer lies in the branch of Artificial Intelligence that has had the greatest development in recent years: Machine Learning algorithms. Traditional algorithms work by defining in a specific way which operations the computer has to perform depending on each situation. The difference with Machine Learning algorithms is that they are designed to receive a large amount of data which, in short, allows a series of parameters to be adjusted to predict the output in the face of new inputs.

It is similar to fitting a point cloud with a straight line, but instead of working in two dimensions, we can have hundreds or thousands of them, with which the great processing power of the computer is able to find patterns that would otherwise go unnoticed. This information can be used by some companies to improve their demand forecasting, production or marketing techniques, which perhaps we can consider somewhat intrusive, as when a page presents us with a article before searching for it, or the cell phone presents us with the card boarding pass when we arrive at the airport before unlocking it. But the real seriousness occurs when they can also be used for potentially illegal purposes in economic, security or political areas, such as the aforementioned Brexit news.

Legislation tends to regulate the collection and management of all this information, but these are measures that are steps behind the technology, so they are not always a secure defence. In addition, the Internet has no physical boundaries and the organisations that can access this information may be in countries outside this jurisdiction. Therefore, the protection of our information is something to which both individuals and organisations need to pay attention. We have to strike a balance between the usefulness of different services and the protection of our privacy and security. To the prevention of not opening unknown files and applications, we should add the habits of not providing our data, including the login on different platforms or the activation of geographical positioning, only to reliable applications or websites and when it is strictly necessary.