The global advocacy organisation AccessNow has filed an expert opinion in a suit where the Brazilian Institute of Consumer Protection (IDEC) has sued the Sao Paulo Metro for a crowd analytics artificial intelligence (AI) system. The system, which was sourced from by US-based AdMobilize, analyses faces and emotions in order to serve personalised ads. In a statement, AccessNow explained that facial recognition depends on biometric data, thereby putting people's privacy at risk. The group has called for a ban on mass surveillance AI systems in public spaces.