This is a term I originally used in a comment on EmergentNo, which, much to my surprise, was accepted quite without complaint be a couple of the other commenters, Emergent though they were. It is the idea, popularized by Brian McLaren, that it is a bad thing to be certain you know spiritual truth--one often gets the impression that it is thought to be a bad thing to be certain you know any truth. It is, in fact, arrogant to be truly certain of something. That it would therefore be bad spiritual practice to say that you are certain your opposition--that is, moi, among others--is wrong about Emergent theology and practice doesn't really seem to connect with proponents of the Uncertainty Principle. Go figure.
I have also found that a politicized version of the Uncertainty Principle is often a very big thing with political liberals. They react to being told they're wrong much the same way that Emergents did/do (there is some question as to whether "Emergent" is still a force in the universe). They call you "arrogant," even though, by their own principles, they cannot actually be sure that you are wrong--about them being wrong, that is. The irony is often totally lost on them.