How we cite our quotes:
Suddenly it was deathly quiet. We had all frozen. Nobody in my family had ever hit me. Nobody. (3.103)
This is a really pivotal moment in the story. It's not that Ponyboy has never been hit before, it's just that he's used to violence occurring out on the streets, not at home. Darry's violence toward Pony pushes Pony out into the night, and is what makes him decide to go to the park at two in the morning.
"Johnny! I nearly screamed. "What are we gonna do? They put you in the electric chair for killing people!" (4.32)
Pony's starting to see a long chain of violent acts stretching out before him. This fear of more violence is a big part of why he and Johnny run.
"You're the guy that killed Bob Sheldon. […] And he was a friend of ours. We don't like nobody killing our friends, especially greasers." (12.4)
Pony responds to this threat by breaking a bottle and then threatening the Socs with it. At this point in the story, he's in bad shape and hasn't been able to process any of the recent events. He seems to be changing, looking more to violence as a way to ward off the violence of the Socs.