Whence cometh the popularity of "douchebag"?

A few years ago I met my friend T's husband, G, who is a good guy and who uses the word "douchebag" a lot. That was a word I had not heard since middle school, but I thought G pulled it off quite well; it sounded so dated it was fresh again--like babies named Sadie or Otis.

G's use of "douchebag" was immortalized in a fictionalized version of G who appeared in a book written by a friend of G's from college. While I think the fictional portrayal was supposed to be kind of negative, the G character was my favorite one in the book. "Douchebag" set him apart from the angsty self-absorption of the other characters.

I started using "douchebag" and its variants now and again after meeting G and reading about Fictional G, but I thought of it as a quirk I was stealing from him. (I figured he wouldn't know because he lives elsewhere.) It has a lot of good applications: you can use it in the way you once would have used other middle-school insults, like "gay" or "retarded," which themselves should not come back into circulation. It's less harsh than "dumbass" or "dickhead," and can be used as an adjective ("douchey.") I think of it as connoting the culture of the dumb, pretentious but not evil, probably drunk, aging frat boy.

Now all of a sudden it's everywhere. There's a video about douchebags reclaiming the word on BoingBoing, and a response on DoubleX critiquing the imprecise use of the term in the video. Can I give credit to G? Fictional G? Me and others who stole it from G and Fictional G? Or is this one of those things, like the popularity of names like Sadie and Otis, that everybody thinks up together and then is annoyed that other people thought of it too?