On the server, there are plugins and world edit and Wrold Guard, doing private areas, but they somehow break: ( I do not understand how, probably cheaters, help put the protection of this. Pleaseeee
That's helpful. Book you might try reinstalling/reconfiguring worldguard, or just use one of the many other area protection plugins, if it's not working for you. I use Residence, and it works very nicely to let players protect/manage their own areas. It does have a hefty configuration file, but you only have to set it up once.
did you protect the whole city? maybe worldguard is not working correctly! what craftbukkit build are you using? Are there any errors in the console?