Essa preocupação não é hipotética: um estudo que interceptou o tráfego de rede de

36 dos aplicativos mais populares de saúde mental (depressão e cessação de

tabagismo) encontrou transmissão de dados a pelo menos um terceiro em 92\% deles,

sendo que 81\% enviavam dados especificamente a serviços operados por Google ou

Facebook — e apenas 59\% desses casos declaravam esse compartilhamento em política

de privacidade \cite{Huckvale2019}.

Um estudo posterior, focado exclusivamente em 27 aplicativos de saúde

mental mais populares da Google Play Store, confirmou o mesmo padrão e

o caracterizou formalmente como uma ameaça de \textit{linkability}

(vinculabilidade) e \textit{identifiability} (identificabilidade): mesmo quando os

identificadores enviados a terceiros são pseudônimos (como \textit{advertising IDs}

ou hashes), eles ainda permitem que provedores de publicidade associem o

comportamento de um usuário através de diferentes aplicativos e serviços

\cite{Iwaya:22}. Como os próprios autores resumem, a mera vinculação de um

usuário a um aplicativo de saúde mental já pode revelar que essa pessoa possui

uma condição psicológica — seja ansiedade, depressão, ou, no caso de um

aplicativo como o Nexo, Transtorno Afetivo Bipolar —, tornando usuários desses

aplicativos particularmente vulneráveis a esse tipo de exposição

\cite{Iwaya:22}.

No caso do Nexo, essa cadeia de inferência é especialmente

sensível: a presença do aplicativo na lista de apps instalados de um usuário,

associada ao seu identificador publicitário, permitiria a uma plataforma como a

Meta inferir uma possível condição de saúde mental do usuário para fins de

segmentação de anúncios, sem que este tenha conhecimento ou consentimento

explícito disso.

@article{Huckvale2019,

	title = {Assessment of the Data Sharing and Privacy Practices of Smartphone Apps for Depression and Smoking Cessation},

	volume = {2},

	issn = {2574-3805},

	url = {http://jamanetworkopen.jamanetwork.com/article.aspx?doi=10.1001/jamanetworkopen.2019.2542},

	doi = {10.1001/jamanetworkopen.2019.2542},

	abstract = {{OBJECTIVE} To provide a contemporary assessment of the privacy practices of popular apps for depression and smoking cessation by critically evaluating privacy policy content and, specifically, comparing disclosures regarding third-party data transmission to actual behavior. {DESIGN} {AND} {SETTING} Cross-sectional assessment of 36 top-ranked (by app store search result ordering in January 2018) apps for depression and smoking cessation for Android and {iOS} in the United States and Australia. Privacy policy content was evaluated with prespecified criteria. Technical assessment of encrypted and unencrypted data transmission was performed. Analysis took place between April and June 2018. {MAIN} {OUTCOMES} {AND} {MEASURES} Correspondence between policies and transmission behavior observed by intercepting sent data.

{RESULTS} Twenty-five of 36 apps (69\%) incorporated a privacy policy. Twenty-two of 25 apps with a policy (88\%) provided information about primary uses of collected data, while only 16 (64\%) described secondary uses. While 23 of 25 apps with a privacy policy (92\%) stated in a policy that data would be transmitted to a third party, transmission was detected in 33 of all 36 apps (92\%). Twentynine of 36 apps (81\%) transmitted data for advertising and marketing purposes or analytics to just 2 commercial entities, Google and Facebook, but only 12 of 28 (43\%) transmitting data to Google and 6 of 12 (50\%) transmitting data to Facebook disclosed this.

{CONCLUSIONS} {AND} {RELEVANCE} Data sharing with third parties that includes linkable identifiers is prevalent and focused on services provided by Google and Facebook. Despite this, most apps offer users no way to anticipate that data will be shared in this way. As a result, users are denied an informed choice about whether such sharing is acceptable to them. Privacy assessments that rely solely on disclosures made in policies, or are not regularly updated, are unlikely to uncover these evolving issues. This may limit their ability to offer effective guidance to consumers and health care professionals.},

	pages = {e192542},

	number = {4},

	journaltitle = {{JAMA} Network Open},

	shortjournal = {{JAMA} Netw Open},

	author = {Huckvale, Kit and Torous, John and Larsen, Mark E.},

	year = {2019},

	langid = {english},

},

@article{Shiffman2008,

	title = {Ecological Momentary Assessment},

	volume = {4},

	issn = {1548-5943, 1548-5951},

	url = {https://www.annualreviews.org/doi/10.1146/annurev.clinpsy.3.022806.091415},

	doi = {10.1146/annurev.clinpsy.3.022806.091415},

	abstract = {Assessment in clinical psychology typically relies on global retrospective self-reports collected at research or clinic visits, which are limited by recall bias and are not well suited to address how behavior changes over time and across contexts. Ecological momentary assessment ({EMA}) involves repeated sampling of subjects’ current behaviors and experiences in real time, in subjects’ natural environments. {EMA} aims to minimize recall bias, maximize ecological validity, and allow study of microprocesses that influence behavior in real-world contexts. {EMA} studies assess particular events in subjects’ lives or assess subjects at periodic intervals, often by random time sampling, using technologies ranging from written diaries and telephones to electronic diaries and physiological sensors. We discuss the rationale for {EMA}, {EMA} designs, methodological and practical issues, and comparisons of {EMA} and recall data. {EMA} holds unique promise to advance the science and practice of clinical psychology by shedding light on the dynamics of behavior in real-world settings.},

	pages = {1--32},

	number = {1},

	journaltitle = {Annual Review of Clinical Psychology},

	shortjournal = {Annu. Rev. Clin. Psychol.},

	author = {Shiffman, Saul and Stone, Arthur A. and Hufford, Michael R.},

	urldate = {2026-07-14},

	date = {2008-04-01},

	langid = {english},

},