Need to protect your server? From all those lame griefing groups? (they just cant play fair, like come on) anyway, there will always be people like that, just like there will always be viruses, or robberies!
So we just have to be prepared for them, this plugin does it with ease! You much have World edit installed (if you don’t already, world edit is another great plugin to have) I will give you a few basic commands to get you started with!
You must first select a area (if you are used to the way world edit it will be no problem) but for those who haven’t use world edit, type //wand or just get a wooden axe out of somewhere. Then right click your highest point with right or left click and your lowest with the other one! Make sure your whole area is included in this block! (if you cant get this part look it up on youtube)
Then type /region claim spawn (spawn is a example and you can put whatever name you like in there) then /region flag spawn pvp deny (this will deny any pvp in this area and for more flags type /region flag spawn sdflk;j (or anything it wont recognize) and it will pop up a list of flags you can allow or deny! But there are many more things to do with this plugin so explore!
Download WorldGuard https://dev.bukkit.org/server-mods/worldguard/