One of the large gangs in the Cape Town area goes by the name "The Americans", and one of the other large gangs calls itself "The CIA". We can't be sure, but it's possible that one of these gang members marked this wall with the name CIA.
Tsotsi is a Sesotho word meaning "thug" or "thief", and the word is often used to refer to a gang member. Tsotsi is also the name of an Academy Award-winning film directed by Gavin Hood that depicts the life of a gang leader in Soweto, near Johannesburg.
It's easy to judge gang members for who they are and what they do. The film Tsotsi gave me a little more insight into the life of one young man who grew up in an environment that practically forced him down a path of crime and gangsterism. The hard side of a gang member is a given, but the movie also depicted the softer side of a young man just trying to survive in the world in which he lives. I seriously encourage you to watch the movie - it really was fantastic.
Watch the short trailer here on YouTube, or a different one on the official movie site.