A friend was suggesting that the best way to discipline children in school is to assemble a firing squad and shoot them after the first infraction. He turned out to be in a minority of one on this. Nevertheless I decided to articulate why this is a bad idea, in case he his fan club decide to back him up on this proposal.
School is supposed to teach kids useful things. Because of this, it has to be a safe place to make mistakes; although there must be consequences, they should be ones we learn from rather than the unforgiving harshness of the outside world.
Schools should teach kids how to live their life. That's why it's boring, you're told to do things you don't like and don't understand, and the teachers (who have no understanding of what it's like to be a child because they never were one themselves, no, they weren't, they can't have been) seem to just arbitrarily make up stuff for you to do. Yes, it's like grown up life but with more stability and less bureaucracy. If we teach kids that mistakes should be punished with violence, that authority rests on brutality, that power comes from the barrel of a gun, then we'll turn out a generation of thugs and victims. Instead we're growing strong kids, kids who aren't afraid, who question authority, who demand and create choices other than those handed out to them. This causes problems; new and different problems (maybe) but I'd rather have those problems than the problems that the lesson of might-makes-right creates.
Also, seriously? A firing squad? Expensive, noisy, dangerous, needing to assemble a group experienced with firearms? I think he's just in love with guns. If I were in the mood for a modest proposal I would take a leaf from the Roman army and have their classmates do the hard work for me.
 Actually he first suggested it for kids who don't do their homework, as though that's the most pressing problem in any school.
 He actually said little sods, thus violating the first rule of talking to those-who-work-with-children: We can be rude about our kids; you can't. Okay?
 Not just because the parents would string up the first bastard who tried it, and, frankly, I'd be handing them the rope.
 Or real life as one kid referred to it. What, is school not real enough for you? :)
 Did I mention I'm something of a fan of old-school SF? Essentially that's all about new ideas and technology causing new and interesting problems. Welcome to my world.
 As in, logistically.