The BnF has implemented a security plan across its 7 sites to protect its 35 million documents, including 15 million printed works and 20 million special documents. The plan focuses on (1) access controls and security in storage areas, (2) preserving and tracking collections, (3) security training for staff and regulations for readers, and (4) national and international cooperation. Key elements include access control systems, video surveillance, stamping collections, electronic tracking of document movement, stocktaking, screening of staff and readers, and cooperation with police. The security of the national patrimony is a major responsibility given past thefts of documents.