Nodus

[redstonewarrior]

... and if we should get plugins to detect if somebody has it.

This is a horrifyingly terrible idea. Come back tomorrow.

Make a plugin then, it's always better than finding one.

I think you completely missed the point.
Our plugins support ORE's infrastructure; they get things done. They keep visitors from banning people, they connect chat to IRC, they generate our map, and they give us massive power over the world through a few simple commands. Adding a plugin for the explicit purpose of identifying if a member is using a certain modded client is a terrible idea. You regulate behavior, not probe your clients to see if they could behave differently. If you're a survival server, and need to watch out for cheaters, then use a plugin that identifies anomalous (non-lag based) actions that seem superhuman. You don't use the "blacklist" approach.
Edit: Italics everywhere.