We, The Living: dystopian writing from Orwell, Rand, Huxley and others
There is an entire line of utopian literature stemming from medieval times starting with Thomas More's Erewhon (Nowhere) to the dystopias of 20th century writing. You could even argue that Augustine's The City was the original.
Still, Orwell did not steal from Rand so much as borrowed from the Russian writer Emil Zamayitan's We, the Living. Rand, a Russian, did the same. The important thing to note is that Orwell spun a tale that included fresh observation of how a regimented society might actually work - based on his direct experiences in London during the blitz and the subsequent War Economy. Rand's work is a good read, but is set in an unnamed time and place, and is a bit fuzzier on reality though her idea of resistance to conformity is powerful.
Interestingly enough, George Lucas stole from Rand's work in his first student project THX-1138, which was later made into his first feature film starring Robert Duvall and Donald Pleasance. Note how in this movie, the automaton police robots are precursors to the storm troopers of Lucas' later Star Wars' series.
Any way, to state it bluntly, good writers borrow, the best ones steal.