Personal Data on Social Media: Risks and Responsibilities

This page is a translation of the original Portuguese text, provided for convenience. It deals with Brazilian law. If there is any discrepancy, the Portuguese version prevails. Read the original in Portuguese

Exposing personal data on social media is one of the greatest legal challenges of our time. The consequences range from financial fraud to irreparable damage to a data subject’s reputation.

The Current Landscape of Data Exposure on Digital Platforms

We live in an age when sharing personal information on social media has become almost automatic. Every day, millions of Brazilians post photos, locations, shopping preferences, family relationships, and even documents, without stopping to consider the legal implications. When you look at the volume of data circulating on these platforms, one thing becomes clear: every post, every like, and every interaction leaves a digital trail. Third parties can collect that trail, store it, and use it for purposes the data subject never imagined.

The General Data Protection Law (LGPD, Law No. 13.709/2018) created a fundamental regulatory framework for the processing of personal data in Brazil, including data shared in digital environments. Even so, many users still do not know how far their rights as data subjects extend. Nor do they know what obligations fall on the platforms that operate in Brazilian territory. The concept of “personal data” covers any information that identifies, or can be used to identify, a natural person. That includes name, CPF (Brazil’s individual taxpayer ID number), and address, but also seemingly harmless data such as browsing habits and geolocation.

Social media platforms work as true ecosystems for the mass collection of information. Their business models rely largely on monetizing users’ data through targeted advertising and sharing with commercial partners. In this context, personal data due diligence becomes an essential practice. It matters both for companies that use these platforms in their strategies and for data subjects who want to protect their privacy.

This subject is directly related to the right to be forgotten, a topic we cover in a dedicated article.

This subject is directly related to privacy in the workplace, a topic we cover in a dedicated article.

Main Legal Risks of Oversharing

Careless sharing of personal data on social media opens the door to a range of risks that come up often in practice. The first and most obvious is the misuse of this information to commit fraud. Criminals use publicly available data (such as full name, date of birth, family members’ names, and location) to run social engineering scams, enter into fraudulent contracts, and even open bank accounts in other people’s names.

Protecting personal data on social media is not just a matter of individual privacy. It is a legal imperative that involves shared responsibilities among platforms, companies, and data subjects themselves.

Another significant risk is the use of personal data for profiling without the data subject’s proper consent. Companies that collect information from public profiles to build commercial databases, without observing the legal bases set out in the LGPD, directly violate the law. This kind of practice often happens silently and automatically through web scraping techniques. It can lead to civil and administrative liability for the processing agents involved.

Sensitive data deserves extra attention. Information about health, political opinion, religious beliefs, and sex life receives special protection under the LGPD (Article 11), whether it is shared or inferred from social media posts. Processing this data requires specific and prominent consent, or one of a narrow set of legal grounds. That makes its indiscriminate collection by third parties even more serious.

Data Breaches and Security Incidents

The history of major data breaches involving social media platforms shows that no company is completely immune to security incidents. These episodes can expose the data of millions of users at once, causing harm on a massive scale. The LGPD requires the controller to notify the National Data Protection Authority (ANPD) and the affected data subjects of any security incident that may cause relevant risk or harm (Article 48). Failing to comply with this obligation can result in significant administrative sanctions.

Damage to Image and Reputation

Unauthorized use of personal data obtained from social media can cause data subjects both moral and material damages. Creating fake profiles, manipulating images with artificial intelligence (such as so-called deepfakes), and disclosing private information without consent all give rise to civil liability regardless of proof of fault. This follows from Article 42 of the LGPD, which imposes strict liability on the controller.

Responsibilities of Processing Agents and Platforms

The LGPD establishes a liability regime that distributes obligations among different agents. Social media platforms, as data controllers, take on direct responsibilities toward data subjects and the ANPD. These obligations include providing clear information about the purposes of processing, ensuring data security through appropriate technical and administrative measures, and respecting the data subject rights set out in Article 18 of the law.

The chain of data processing on social media often involves multiple agents: the platform itself, developers of integrated apps, advertising companies, commercial partners, and even other users who share third parties’ data. Each of these agents can be held jointly and severally liable for damage caused by irregular processing of personal data, as provided in Articles 42 to 45 of the LGPD.

Companies that use social media as a marketing or customer service channel also act as processing agents. Collecting followers’ data for advertising campaigns, running giveaways that require personal information, and monitoring brand mentions are all activities that must respect the principles of purpose, adequacy, and necessity under the LGPD. Conducting due diligence before implementing these strategies is essential to identify and mitigate compliance risks.

The ANPD’s Enforcement Role

The National Data Protection Authority has steadily expanded its enforcement activity, with special attention to data processing in digital environments. The sanctions provided in the LGPD include a warning, a simple fine of up to 2% of the legal entity’s revenue (capped at R$ 50 million per violation), publicizing of the violation, and blocking and deletion of the personal data. Regulatory enforcement is likely to intensify in the coming years, which makes it even more urgent to bring data processing practices on social media into compliance.

Personal Data Due Diligence: Best Practices and Recommendations

Data protection due diligence in the social media context involves a set of preventive procedures. They let you identify vulnerabilities and put corrective measures in place before harm occurs. For companies, the process starts with a complete mapping of the personal data flows involving social platforms, including identifying the legal basis used for each processing operation.

We recommend that this mapping cover, at a minimum, the following: what data is collected through social media, what purposes it is used for, who it is shared with, how long it is stored, and what security measures protect it. Preparing Data Protection Impact Assessments (RIPD), as provided in Article 38 of the LGPD, is especially advisable when the processing involves sensitive data or takes place on a large scale.

For data subjects (the social media users themselves), due diligence means being more aware and cautious about sharing information. Among the practices we suggest: periodically review the privacy settings of the platforms you use, limit the personal data exposed on public profiles, carefully evaluate the permissions requested by integrated apps, and actively exercise your rights under the LGPD (such as access, correction, and deletion of data).

Consent and Transparency

When consent is used as the legal basis for processing, it must be freely given, informed, unambiguous, and tied to specific purposes. On social media, terms of use are long and frequently changed. As a result, genuine consent is often undermined by the lack of clarity in the information presented to data subjects. Active transparency practices, such as simplified privacy notices and granular opt-in mechanisms, support legal compliance and strengthen trust with users.

The Marco Civil da Internet and Complementary Legislation

When we examine the legal framework that applies to data protection on social media, we cannot ignore the role of the Marco Civil da Internet (Brazil’s Internet Civil Rights Framework, Law No. 12.965/2014). It sets out principles, guarantees, rights, and duties for internet use in Brazil. This law complements the LGPD by addressing topics such as the inviolability and secrecy of private communications, the protection of connection records and application access records, and the liability of application providers for content generated by third parties.

The interaction between the Marco Civil and the LGPD creates a robust regulatory system that places obligations on social media platforms on multiple fronts. For example, the retention of access records must respect both the time periods set by the Marco Civil and the LGPD’s principles of data minimization and limited retention. This complementarity requires companies to make an integrated compliance effort that considers both laws together and consistently.

The Consumer Protection Code (Law No. 8.078/1990) also applies to the relationship between social media platforms and their users when it qualifies as a consumer relationship. Strict liability for defective services, the duty to inform, and protection against abusive practices are additional tools that reinforce the protection of Brazilian users’ personal data. Together, these rules significantly widen the avenues for holding platforms liable for improper processing of personal data.

As informações deste artigo são de caráter informativo e não substituem consulta jurídica individualizada. Cada caso possui particularidades que exigem análise específica.