This question already has an answer here:
It's come to my attention that someone has copied something I wrote on music.SE, without attribution, and posted it to his own website.
I learned of this today when someone posted a new answer to this question, to which I had posted an answer of my own on January 22, 2011 (the same day the question was asked). In the new answer, the poster makes reference to an outside resource and observes that the outside resource contains (on page 4) the same material, verbatim, as my answer—as indeed it does, to my dismay.
Obviously, we're all volunteers here and our contributions aren't copyrighted. But in the interests of preserving my reputation and the reputation of my fellow contributors, I'm wondering whether these kinds of situations have come up before and how we can deal with them, if in fact we can deal with them at all.
Thanks, and here's hoping this isn't too common.