(19)To guarantee an early and effective detection of anomalous activities, financial entities referred to in Title II of this Regulation should collect, monitor, and analyse the different sources of information and should allocate related roles and responsibilities. As regards internal sources of information, logs are an extremely relevant source, but financial entities should not rely on logs alone. Instead, financial entities should consider broader information to include what is reported by other internal functions, as those functions are often a valuable source of relevant information. For the same reason, financial entities should analyse and monitor information gathered from external sources, including information provided by ICT third-party providers on incidents affecting their systems and networks, and other sources of information that financial entities consider relevant. In so far as such information constitutes personal data, the Union data protection law applies. The personal data should be limited to what is necessary for the incident detection.