As part of the Great Firewall, beginning in 2003 China started the Golden Shield Project, a massive surveillance and censoring system, the hardware for which was provided by mostly U.S. companies, including Cisco Systems. The project was completed in 2006 and is now carried out in buildings with machines manned by civilians and supervised by China's national police force, the Public Security Bureau (PSB). The main operating procedures of the gatekeepers at the Golden Shield Project include monitoring domestic websites and email and searching for politically sensitive language and calls to protest. When damaging content is found, local PSB officials can be dispatched to investigate or make arrests. However, by late 2007 the Golden Shield Project proved to operate sporadically at best, as users had long adapted to internet blocking by using proxy servers, among other strategies, to make communications and circumnavigate to blocked content.