Steven slamming a bully up against a locker in the first episode.
Earlier in the episode, Guber puts the same bully in his place:
Look at me...LOOK AT ME, sir. Do we need to work on eye contact? You'll continue looking at me until further notice.
Marla's speech to the school board in the third episode.
Marla: Let me tell you something, let me tell all of you something—the reason I've had I is because I have to go into a room day after day after damn day and try to break through to a bunch of kids who don't want to listen, don't want to learn and don't want to give me the decency of being quiet! Harry Senate shot off a gun? I woulda rolled in a big cannon if I knew where to get one! I would've tried anything! And you show me a teacher who doesn't almost lose his or her mind sometimes, and I'll show you a teacher who's not trying! I can show you some parents who aren't! You send 'em to school thinkin', "Job's done—it's up to the teachers now." Well, it doesn't work that way! You gotta get in this, too! Kids comin' every day, singin' that jingle—"Those who can't do, teach." They get that from their parents! I know what you think of us! Well, let me tell you—we're in there doing every damn day! And a lot of the doing we do is PARENTING! You want to compare failures? Step right up! Who's first?
Board Member: Thank you, Miss Hendricks.
Marla: (to Superintendent Shinn) And that little whirl you took coming through the school so you could come to this meeting and say "I've been there"—lady, you ain't been there! (as she goes back to her seat) Stuck-up, intellectual, superintendent, frappuccina bitch!
Christine finally standing for herself:
Christine: If you come again—my name is not "The Blob." I don't like being called that. I know it's maybe fun to cheer that, but it's not fun for me. My name is Christine Banks. You want to cheer for me? I ask you to do so using my name. Thank you.
A Season 4 episode had a Middle Eastern student named Khalid being suspected of being a terrorist (he was innocently looking at a terrorist recruitment website in the school library). Students gang up on Khalid's sister Sabeen and hurl insults at her, and one even throws a bottle at the girl's feet. Harvey exits the school and pushes a student to the ground, yells at the tormentors and tells them they're the terrorists before escorting Sabeen back into the school.