Adnan Oktar (born Ankara, February 2, 1956), also known by his pen name, Harun Yahya, is a Turkish proponent of Islamic creationism, anti-Zionism,, Pan-Islamism and, more particularly, supports Old Earth creationism. Oktar denounces Zionism as racism and Freemasonry, and Darwinism as the source of terrorism. In 2007 he sent out thousands of unsolicited texts advocating Islam and creationism to schools and colleges in several European countries and the USA. Oktar has defended his views by litigation; he is responsible for the blocking of numerous, high-profile Web sites in Turkey.
Oktar runs two organizations: Bilim Araştırma Vakfı ("Science Research Foundation", BAV, established 1990), which promotes creationism and Milli Değerleri Koruma Vakfı ("Foundation to Protect National Values", established 1995), which focuses on "moral issues".
After publication of his book, Judaism and Freemasonry, in 1986 he spent 19 months in jail for promoting a theocratic revolution, despite not being formally charged. In 2008, he was convicted of creating an illegal organization for personal gain, and he and 17 other members of his organisation were sentenced to three years in prison.