2026-04-13T05:54:25Zhttps://recercat.cat/oai/request

oai:recercat.cat:10256/269022025-06-13T04:05:34Zcom_2072_452955com_2072_2054col_2072_452957

2025-06-13T04:05:34Z urn:hdl:10256/26902 Large-scale web tracking and cookie compliance: Evaluating one million websites under GDPR with AI categorization Martínez Álvarez, David Molero Grau, Aniol Calle Ortega, Eusebi Canals Ametller, Dolors Jové, Albert Protecció de dades Intel·ligència artificial Data protection Artificial intelligence Internet -- Mesures de seguretat Internet -- Security measures With the increasing prevalence of web-tracking technologies, including tracking cookies, pixel tracking, and browser fingerprinting techniques, there is a pressing need to analyze their impact on user privacy. Despite the growing interest in the scholarly literature, large-scale, fully automatic evaluations of website compliance with privacy regulations remain scarce. In this paper, we present new algorithms, methods, and an AI categorization model designed for massive, fully automatic analyses of web-tracking and cookie compliance and usage with and without valid user consent. Utilizing the recently published Website Evidence Collector (WEC) software from the European Data Protection Supervisor (EDPS), these algorithms are applied to assess over one million websites from Tranco's top list under European GDPR regulation. A novel 22-category multilabel AI model for website categorization provides content-based context to compliance results, achieving 96.56% accuracy and an F1 score of 0.963. Results reveal that nearly half of the websites utilize tracking cookies, while over half employ pixel tracking without user consent, thus highlighting significant differences between websites' content categories. Additionally, our analysis demonstrates how web-tracking power is concentrated among just a few companies, with the top 10 tracking firms being responsible for most compliance violations related to obtaining valid user consent. This paper serves as a foundation for ongoing large-scale web-tracking analyses, essential for understanding trends over time and evaluating the effectiveness of privacy regulations The University of Girona Institute of Informatics and Applications researchers thank the Generalitat de Catalunya for their support through a Consolidated Research Group (2021 SGR 01125). David Martínez thanks the University of Girona for his FI fellowship (IFUdG 46 2022) Open Access funding provided thanks to the CRUE-CSIC agreement with Elsevier 2025-06-13T04:05:34Z 2025-06-13T04:05:34Z 2025-10 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion peer-reviewed http://hdl.handle.net/10256/26902 info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jnca.2025.104222 info:eu-repo/semantics/altIdentifier/issn/1084-8045 Reconeixement 4.0 Internacional http://creativecommons.org/licenses/by/4.0 info:eu-repo/semantics/openAccess Elsevier Journal of Network and Computer Applications, 2025, vol. 242, núm. art.núm.104222 Articles publicats (D-ATC) Martínez Álvarez, David Molero Grau, Aniol Calle Ortega, Eusebi Canals Ametller, Dolors Jové, Albert 2025 Large-scale web tracking and cookie compliance: Evaluating one million websites under GDPR with AI categorization Journal of Network and Computer Applications 242 art.núm.104222