To be an Emo or a Chav? That is the question

I went to school yesterday. Although I'm not supposed to teach, I'm allowed to do the French speaking mock exams next week and I wanted to see my class once before that. The lesson went well, although the kids were quite chatty and a mixture of "we don't care but it's nice to see you, miss". Not sure that's how I wanted it to go. Of course, lessons are a lot easier when instead of having to jam up a lot of last minute tips, pupils can do games where they might win a sweet. Although technically we're not supposed to give sweets, Jamie Oliver and healthy eating and all that.
The day started with an emergency staff meeting. Apparently, two gangs had a bit of a fight the day before at lunchtime on the staff car-park, and they ended up with a broken nose and a broken windscreen. Although I don't know if the two were in that order or even related. The gangs in question are called the Emos and the Chavs. Emos, I am told, wear their hair long and are middle-class, sensitive types. Chavs, aka the Townies, wear Argos jewellery and Nike tracksuits, and not particularly the eloquent and poetic type. For more info, I would recommend http://www.urbandictionary.com, which explains it all a lot better. Although I'm not sure I understand it all.
Anyway. Rumor went round the school that the Chavs were planning to bring in a knife on that day. Which sounds really dramatic, but the Headteacher went on to explain that "the knife was intended not to attack someone, but to cut an Emo's hair". For the example.
I know. I burst out laughing at that point but no one else in the staff room seemed to find it funny or absurd. So I quickly regained composure. Apparently, cutting someone's hair with a knife qualifies as assault, so the police were brought in all day, just so kids would see the fluorescent jumpers and get a bit scared. I'm not sure it worked. All I heard all day in the corridors was the existential question, "Are you an Emo or a Chav?"
There. It's all about priorities. Maybe I should have asked that question in French to my class in the afternoon, it might have sparked a little interest...