As Katrina said, helpOP, helpOP, helpOP. KitPvP is an underplayed and understaffed server, meaning A. hackers can wreak more havoc, and B. hackers can hack for longer, as there aren't many if any staff to prevent this from happening. However, you are one command away from alerting ALL staff that you have a hacker on your server. This works on all servers, so in the case that there are no staff on your current server, remember /helpop and you'll save yourself and others plenty of trouble.