I've heard various ideas such as limiting it only after mods have expended their points (this will require implementing a cooldown to prevent a user from getting points again too soon). I want to hear your feedback, and I'll roll together something for the next major update of the site. Leave your comments
In a past discussion I wanted Karma expressed as decibels referenced to AC rather than an absolute power level. An uncap it. So I'm coasting along at +17 dBK0AC or 17 dB Karma above AC. And then you could express rules as "block all posts with an absolute Karma level of 5 dB below AC" or "+1 display posts by authors with a relative dB Karma level at least 3 dB over my Karma level".
Depending how smart they are, it takes a noob to the telecom fields only a short length of time to get used to this stuff. Biggest problem is some fields going total power for zero ref and some fields going voltage for zero ref, but we've got the obvious selection for zero ref of Anonymous Coward.