block specific users in my LAN to copy or if not, to access my computer

[potzo]

I'm connected trough a switch to a local network with some neighbors. I want to know a trick, a setting I can do or maybe a software that could block specific users to access or better, to disable copy capabilities from my computer. So, I want to keep shared files in my network but as long as some people won't share files with others, I want to "punish" them in a way or another. My operating system is XP. 10x