The majority of applications used on the Internet are centralized; almost everyone uses social networks, but a single individual often provides some of the most widely used social networks. Consequently, hundreds of millions of people depend on this individual, their ideas, and moods. There is also the possibility, as has happened, of censoring and blocking political power. The same goes for banks: millions of people are clients of a bank, which is directed at the top by very few individuals. Of course, to freeze an account, it is not enough for the will of the bank manager; a specific order from the authorities is required.

The ban on Donald Trump from Twitter and Facebook has prompted many people, even those with opposing political views, to reflect on the immense power held by those who control social networks. These platforms are private and have become a part of our daily lives, even in political and governance matters, to the extent that there is a call for some form of public regulation. Concerning user privacy, restrictions are often called for to be imposed on web giants. Edward Snowden publicly demonstrated how the USA implemented surveillance programs on its own citizens and foreign states, showing how institutions themselves take advantage of data theft.

In the case of regulations protecting privacy, it is referred to as privacy by policy. Unfortunately, there is no way to know which data is actually collected and whether regulations are respected. Even if a profile is deleted from a social network, it is not possible to know what happens behind the scenes: have our data truly been deleted, or are they kept there in case they are needed in the future? Mass surveillance is now very, too economical not to be applied. This is where the concept of privacy by design comes in, meaning an information system designed not to be spied on or censored.

In the field of computer science, the imbalance of power and resources among humans is so evident that it is easier to notice and potentially address. It is precisely to escape central control that many people have embraced the philosophy of peer-to-peer systems, for example, to enable the sharing of copyright-protected files. These systems see the presence of more ‘equals’ who, with equal power, exchange information freely and directly without the need for any intermediary. This paradigm is also used for some messaging applications, ensuring that communications cannot be intercepted in any way.

The most widely used systems at the moment, such as the aforementioned social networks or various chat applications like WhatsApp, Telegram, etc., are completely centralized. This means that messages pass through their respective servers. They offer, on paper, an end-to-end encryption system, meaning that data is encrypted before being sent to the server. Experience and scandals in recent years should teach us not to trust what cannot be verified with our own eyes. An application with end-to-end encryption, but whose leaders are prone to political system requests, is likely to have backdoors (essentially ‘service entrances’ or intentional ‘flaws’ created by programmers) to read the messages of its users.

Perhaps the most revolutionary application of peer-to-peer systems is that of blockchains, which allow the construction of a decentralized substrate on which to build other things: not only free file exchange but also the exchange of skills, value, and, ultimately, organizational and political decision-making.