In the novel The Outsiders, Why do four Socs attack Ponyboy?

Ponyboy is attacked because he is walking home from the movies alone. Ponyboy is attacked when walking home from the movies by the Socs because he is a greaser, and the two gangs are engaged in an ongoing retaliatory turfwar. He is vulnerable because he is alone ... Socs and Greasers are constantly at battle.