"YOU MANIACS! WHAT ARE YOU DOING!? THIS IS LITERALLY 1984"

Explanation: George Orwell, noted socialist writer (and author of the much-abused allegory 1984 ), actually fought in the Spanish Civil War alongside the Trots and Anarchists. He only barely survived a purge by their ‘allies’, spurred on by Stalinists, and escaped the country afterwards.

His memoir on the subject, Homage to Catalonia, is quite excellent.