I read on several .edu websites that, although public domain information can not be copyrighted, still unique compilations of such information are copyrightable.
This has happened to me before, but it's the first time when someone copies my work and, a few months later they are right below my pages in Google's search results. I attribute this to their being a well known, fairly large company. The pages they put up are full of almost unintelligible sentences grouped around my content. What do you do in a situation like this? Is it worth sending a DMCA to Google?
almost unintelligible sentences grouped around my content
Hm, now that sounds like g's definition of "pure spam". Or did you mean simply corporatespeak? To normal people it's gibberish, but the people who use it sincerely believe it to be English.
When you talk about "public domain information", are you talking about the information itself-- which by definition can't be copyrighted-- or the exact wording of the information? Admittedly there's an overlap; there are not many ways to say "The phone number of the Department of Administrative Affairs is 555-1212".