Only ever once gave a detention where 2 pupils were playing up for a suply teacher. They had deleted each others work and then come to ask me to restore it. I told them that as they had wasted my time looking and loading the files, I would waste theirs and got them in at lunchtime to clean keyboards
Never happend since. But then I treat the kids the same as they treat me(mostly) If they are nice to me I am nice back. I'm not paid to discipline the kids and will only say something if it could cause problems with my work (ie. kids swinging their bags stood next to monitors) But then I have told staff that anyone I find misusing the computers/network will have their access removed...no debate. But I am lucky and am supported by the ICT Co-Ordinator. Talk to the teaching staff and explain that you want support for any discipline you give the pupils. They may be able to suggest ways that will work for your pupils, or at the very least back you up when you do shout/give detention etc.