Landru was a really smart guy from Betamax III who died about 6,000 years ago. Before that, though, he made a really smart computer that would regulate the society of his world, maintaining peace and tranquility while removing every vestige of personality from the populace.
Landru's computer had a holographic projector that could transmit the late Landru's likeness (dressed in snappy curtains), to any place without a receiver. This impressed Starfleet officer James R. Kirk no end, making one wonder how well he understood the workings of his own transporter.
Landru's plan worked brilliantly and the people of Betamax lived in a kind of "Virginia City" like stupor for several millenniums until the USS Debate Club appeared and tried to bring ah, some good, ol' fashioned anarchy and chaos to this lovely ... little ... planet.
The Debate Club failed to bring about the much-hoped for revolution, but they did plant enough seditious seeds for James R. Kirk to finish the job. And finish it he did by talking a computer to death. (TOS: "You Are Not of The Body!")