This group of posters should get together and start a blog on splogs and ways to deal with your material being web-jacked. You should have used this offender for an example of a spam blog, (probably more at scraping) That way you could make money off of them instead of them upsetting you for nothing.
Google isn't going to do anything to you for this duplication. If that was true, you could easily eliminate competition by duplicating their material on another domain. It would have to be the same (exact same) pages and not just the text before it would be noticed as duplicate. You would also have to report it to them before they noticed.
Otherwise, I have never heard of it happening. I have heard of a lot of people who think that it happens, but I have never once read of a real example.
If you could get into trouble from someone copying your content, then you could start a business using this method to eliminate other peoples competition.
Google's rule is that if you could do it to somebody to hurt their ranking then they wont count it. Apparently, they have other ways of dealing with these problems. So they say. I'm waiting to see it, then I will believe it.