I don't understand why people always think that: Gryfindors are good people, and never do any thing wrong, if they bully some one, that's because the victims  deserve it.
1/in book 1, Hagrid gave Dudley a pig tail, although he can fix it in 1 second, he did not bother to fix. Then Dudley's parents need to bring him to hospital, and suffered the ridikulus from doctors, and Dudley scared for life. But people still think that 11-years old child Dudley deserve that and Hagrid is a hero. Wtf?
1.2/in book 4, Hagrid made the decision to give Harry Potter a heads up about the dragon challenge, arguably the most dangerous of the lot, giving him a distinct advantage against his competitors. That's cheating! But because Hagrid is helping Harry, so that's ok?
2/ Dumbledore knew that the Marauders were illegal animagus, but he still did not punish them. And in book 3, when Sirius escaped Azkaban, knowing that Sirius is a animagus, still believing that he is  mass murderer, but Dumbledore and Lupin did not tell anyone about that.
3/in book 6, Harry after nearly killed Draco, but had no regret => it's fine, then.
4/in book 6, Harry followed Draco everywhere, even ordered Kreacher to follow him because Harry thinks that Draco is up to no good => it's ok
But Snape followed the Marauders because they bring a werewolf outside the shack => Snape is evil.
Snape waited outside Gryfindor dorm to say sorry to Lily => Snape is creppy.
5/Tonks (not Gryfindor, but a Huf) changed patronus to match with Lupin => that's true love.
Snape changed patronus to a doe => that's creepy.
6/the twins are clearly bullies.
They charmed Ron's toy to a spider => lead to Ron scare for life. And they almost let Ron take an unbreakable vow, knowing the consequences => but they are funny, so that's ok?
7/Lupin was a prefect, but never stop these bullies. He abandoned his wife and unborn child, but still a good person?
He did not bother to drink the potion on time, almost kill Harry, Ron, Hermione. But Harry always blamed Snape because he telling people Lupin's secret? If Lupin drink potion on time, Snape never tell any one.
8/Sirius abandoned family and always blamed his parents, but still have no shame, inherited all the money and the house of his parents?
He never regret about bullying Snape => that's ok, Snape deserve that.
He treated Kreacher terribly => it's ok.
I never understand the double standard of these people.
I hated the end of the books for many reasons and that was one of them: the dark side kills people – but the light side also tortures creatures (ex: gnomes), says amortencia is cool and can be sold to anyone, teachers can turn students into animals and is ok, if your bully is from Gryffindor there is nothing you can do about but welcome 7 years of h*ll because they are all angels and can do no wrong (cough*Pettigrew*cough), Hermione scarred a girl for life because she wanted to protect her mother and that was "cool", Hagrid grew dangerous beast where they could hurt children and made Harry and Ron go after the giant spider and almost get eaten, made Harry go with him in the forest to look at a dragon, made the trio watch over his dangerous giant half-brother and we are not even talking about making the trio clean up his messes while he stays around twiddling his thumbs but he was a "good guy", Minerva made Neville stay outside his dorm while there was a murder in the castle just because he wasn't brave enough for her taste, and many many more but Snape was the worst teacher cause he was mean to the hero. Harry died to keep the awful status quo of the magical world, nothing changed and nothing is better, and the way the book sees "bad guys" is if they are bad to hero or not, if they are good then anything they do to other people doesn't matter how awful or much they suffer is excusable.
9/ethical dilemma number 1: Hermione cursed the paper to only punish someone after they had broken the contract, without telling those signing the contract that they would be punished. This type of curse seems to only work as a tool for revenge, as it does nothing to incentivisize those signing it to keep their word. Knowing about the curse before-hand might have stopped those hesitant to follow the rules from signing it and furthermore the knowledge of the curse might have kept people from talking, as they would have known that something bad might have happened. There were no downsides to telling people what exactly they were signing. Hermione's decision to keep the curse secret was not smart and seems to only satisfy her need for revenge.

Ethical dilemma number 2: Marietta's punishment is somewhat permanent. The pimples lasted for well over a year in her face and it is said that while they faded with time, they did leave scars. This means that Marietta was very slightly disfigured for life as a consequence of Hermione's curse. The question of wether it is propotional to disfigure a child over betraying a secret dueling club is something to ponder upon. Marietta did not directly put anyone's lives at risk, which is more than can be said for many other characters who do not face any consequences for their actions. Marietta's punishment seems dispropotional considering her crime, even if we bypass the fact that she was not punished by a objective third party, but was a target of vengeance by someone very much emotionally invested in the situation.

Ethical dilemma number 3: What were Marietta's motives. Neither the narrative nor the characters are especially interested in finding out Marietta's motives from Marietta herself. We hear from Cho, that she did what she did for her mother's career, which our protagonists are simply pissed off about, deeming this insufficient reason. It very well might have been just to give her mom a boost in the ministry, but what if Marietta had a really pressing reason. What if someone's life was in danger? What if she was being threathened? These are all reasonable things that might have happened, and as a reader, I would have liked to hear more about Marietta's side of the story, becaus enow I am left very much wondering wether we punished someone whi truly did try their best in an impossible situation.

Ethical dilemma number 4: During the interrogation in Dumbledore's office, Kingsley uses a memory charm on Marietta, so that she cannot tell Umbridge any details from the DA. Therefore, Marietta is now being punished for something she doesn't even rememeber. Punishing someone for a crime they don't even remember is an ethical dilemma and a half and I'm sure I don't even need to lay it out for anyone why that would be.

By consequences, I don't mean that Hermione should have been punished in turn or that the whole incident shouldn't have happened. Hermione is a dumb kid, who does dumb impulsive things. That's a realistic way for a teenager to act. But I am frustrated that not once does Hermione stop and think about what she ahd done afterwards. Or that the incident doesn't affect Hermione's life in any way after the fact. No one aside from Marietta and Cho disagreed with this act, Hermione never needed to face Marietta again, either as an enemy or a friend, the whole thing was simply swept under a rug without it affecting anyone in any meaningful way.