Every ISP must be approved by both the Telecommunication Company of Iran (TCI) and the Ministry of Culture and Islamic Guidance, and must implement content-control software for websites and e-mail. ISPs face heavy penalties if they do not comply with the government filter lists. At least twelve ISPs have been shut down for failing to install adequate filters.[17] The state blacklist consists of about 15,000 websites forbidden by the Iranian government.[6] Before subscribers can access Internet service providers, they must first promise in writing not to access "non-Islamic" sites.[18] In 2008, Iran has blocked access to more than five million Internet sites, whose content is mostly perceived as immoral and anti-social.