One of the ideas raised in Brecht's play is the effect of technology on our sense of humanity. Are new technologies exciting and empowering, or are they threatening and dehumanizing? Perhaps this anxiety was a response to the mechanized slaughter of WWI (1914-1918) and the proliferation of more automated systems of labor -- for example, Henry Ford introduced conveyor belt systems in his main plant in 1913.
This ambivalence was evident in other works from the 1920s and continues to exist into our own era, in which we see the theme of man vs. machine, or man becoming machine.
The Adding Machine: Mr. Zero is driven to madness and murder when, after 25 years at his job, he is fired and replaced by a machine. Elmer Rice's 1923 play is a seminal work of American expressionism, and in 2007 it was successfully re-imagined as a musical.
R.U.R.: Human-Machines who are designed to serve people turn rebellious and threaten to destroy the human race. Karel Capek's 1921 science-fiction play is credited with introducing the word "robot."
Metropolis: Fritz Lang's famous 1927 film depicts a workers' nightmare in which a giant machine called Moloch literally devours people.
Modern Times: In this 1936 film, Charlie Chaplin's Little Tramp offers a more comic version of the struggle between man and machine.
And the combination of fascination and fear continues to this day...