The Jargon File (version 4.4.7, 29 Dec 2003):

Evil Empire
 n.

    [from Ronald Reagan's famous characterization of the communist Soviet
    Union] Formerly IBM, now Microsoft. Functionally, the company most
    hackers love to hate at any given time. Hackers like to see themselves as
    romantic rebels against the Evil Empire, and frequently adopt this role to
    the point of ascribing rather more power and malice to the Empire than it
    actually has. See also Borg and search for ?Evil Empire? pages on the
    Web.