In May 2004 Kenneth Brown of the Alexis de Tocqueville Institution raised the accusation that major parts of the Linux kernel had been copied from MINIX , in a book called Samizdat . In May 2004 , Kenneth Brown of the Alexis de Tocqueville Institution made the accusation that major parts of the Linux kernel had been copied from the MINIX codebase , in a book called Samizdat .