I have just started republishing my deleted eHow articles, only to find that some of my best earners were copied all over the internet, by places that should have known better. It took me several rounds of emails to get the duplicated content deleted from Yahoo!, but iVillage and others responded quite quickly. What I want to do is compliment HubPages on their site, as to how I learned from this experience. I copied my article from its cache on the Internet Wayback Machine and published the article (along with some great photos from art.com). Almost immediately it was marked as a duplicate. I sent an email showing them the cached page and that I was the original author, and they responded by immediately overriding the duplicate flag within minutes.
So I am impressed with the HubPages team for, first, alerting me that my content had been duplicated, and sending me at least one link to the duplicated content; and second, for reinstating my hub within minutes of the proof that I was the original author. And thank you to the sites that took down my duplicated content (including a lot of sites that should have known better). And boo to the sites that refuse to take it down, or have no way to contact them to ask that they take it down.
The fact is, it's almost impossible to enforce copyright on the Internet. But by posting it on a highly-trafficked site like HubPages, Squidoo, InfoBarrel, or another article site, it's quite possible that you will eventually outrank your duplicated content with your republished original content.
I'm off next to Google to ask them to de-index the offending sites until the duplicate content is removed.
Update: I'm lazy, so here's my way to combat the thieves.