By default SAP BW provides logging capabilities of data access. Means all users access to data can be logged and evaluated from security and audit point of view. For regular usage of system usually this is enough. Some countries are requiring IT systems to fulfill their own rules while processing personal data. One of example is Spain which few years back introduced so call Ley Orgánica de Protección de Datos de Carácter Personal (LOPD) law.
As BW is one of systems that can store personal information; SAP had to provide capabilities within the SAP BW system to adhere the law. This resulted in introduction of LOPD Access Logging in Reporting and Planning Applications as feature of the SAP BW and/or SAP NetWeaver.
The LOPD feature involves logging all access to sensitive personal data stored in SAP BW. Technically it is delivered via BADI RSEC_LEGAL_AUDIT_SAP. By implementing mentioned BADI the LOPD feature is enabled. As next steps particular InfoProviders which store personal data need to be customized as LOPD relevant via customizing table RSECLOPDIP. Once these things are setup system collects the LOPD relevant data.
933441 - Frequently asked questions on BW 7.0 and data protection