The # symbol is commonly used in texts written on the Internet today and on digital social networks in general. Since 2007, when it was first used to group conversations, the hashtag has evolved, crossed borders, and connected millions of people around the world. However, it has also become the visible tool of algorithms that “classify” us and drive our opinions on the web.

In reality, the # is not new in the field of computing. Since at least the 1970s, it has been commonly used in programming languages such as C and C++ to mark directives to the preprocessor. Those of us who remember the arrival of push-button landline phones will also recall that it was used in telephone systems as a function key.

Nor was the former Twitter (now X) the first to use this symbol on the internet. Since the 1980s and 1990s, it has been seen in IRC (Internet Relay Chat) to label online chat channels. But all of the above pales in comparison to what today's X did when social media expert Chris Messina wrote: “What do you think about using # for groups? Like #barcamp (msg)?”. Thus, this communication adventure was born.

At first, Twitter did not officially adopt it, but users began to use it organically; in 2009, it decided to implement it as links from which searches on specific topics could be accessed. A year later, hashtags were an official feature, later spreading to other networks such as Instagram, Facebook, and TikTok.

The prominence of Twitter-X as a forum for expressing opinions and information made hashtags a key tool for social movements, live events, and digital marketing, and they even began to appear in news headlines.

Today, they remain a key tool in digital social media, but their use varies depending on the platform and current trends. Following the cataclysmic acquisition of Twitter by Elon Musk, the # continues to be relevant in public debates and news stories. In other universes, such as Instagram, they are widely used to discover content, and posts with at least one hashtag are considered to be 12.6 percent more likely to be shared by users.

On Facebook, their role is less noticeable, but they are still used in groups and advertising campaigns. Where they do retain their primacy is on TikTok, as they are key to the algorithm.

This importance even extends to the digital “microworld” that is China. There are features similar to hashtags, although with key differences. On Weibo (equivalent to X), they are used in the same way to organize topics or events; however, on Douyin (TikTok for the rest of the world), the algorithm is programmed to prioritize content based on interests rather than tags. Meanwhile, on its equivalent to Instagram, Xiaohongshu uses thematic tags, but less like traditional hashtags; this is not the case on the hugely popular WeChat, which combines the best attributes of Western social networks, as content is shared there in so-called moments.

“BLINDED” BY HASHTAGS?

Turning to the Cuban digital ecosystem, it is impossible to avoid the question of whether hashtags really influence Cuban public opinion.

The most widely accepted statistics indicate that their impact on shaping the perception of reality among internet users in our country is low, especially because Twitter-X, where hashtags are most common, is not the main network used by Cubans in Cuba to obtain information or express their opinions.

In shaping the notion of what is happening, Facebook is the most relevant for domestic audiences, followed by Telegram, WhatsApp, and Instagram, along with spaces such as YouTube, where hashtags carry comparatively less weight.

The most “viral” hashtags often associated with Cuba express extreme political opinions in a veritable asymmetric content war. On one side, there is a powerful counterrevolutionary machine with deep pockets that uses algorithms to establish hashtags that appear to be predominant, but in their least aggressive form, only focus on the “bad news” generated within our archipelago.

On the other side, revolutionary forces have been trying for years to gain a foothold on a playing field with a slanted court and referees at the service of their opponents. These conditions cast doubt on the relevance of an effort that seems to have little or no impact on the average Cuban living here.