All prisoner letters - received and sent - were strictly censored. In fact, during the 1960s, prisoners could only read and receive letters written in the official languages recognized by the state: Afrikaans and English. This eliminated the possibility of inmates using their native language (Zulu, Xhosa, Sotho, etc) to skirt censorship. Here you can see a big hole cut in a letter to prisoner Srinivasa Moodley, who later said: "The guy who unleashes a dog on me, I can deal with. But when a guy comes to you and exercises his power over you by giving you a letter with a big window cut into it, it was the cruelest form of punishment."