Zaidi has covered the Mumbai mafia for several decades. His 2002 book "Black Friday" detailed the 1993 Mumbai bombings, an attack consisting of thirteen explosions that killed 250 people. The book was adapted two years later, in 2004, into a film by Anurag Kashyap also titled "Black Friday". The film was so controversial that the Indian Censor Board did not allow it to be released in India for three years. It was finally released on 9 February 2007 after the Supreme Court of India allowed it following the TADA court verdict in the '93 Bombay blast case. In "Dongri to Dubai: Six Decades of the Mumbai Mafia", a historical account of the Mumbai mafia, Zaidi conducted an interview with crime boss Dawood Ibrahim, who is suspected of having orchestrated the bombings. The book was adapted into the film "Shootout at Wadala" by Sanjay Gupta.