I will respond to all here and I sincerely appreciate what each of you has shared. 
There is no law that one of our firms is aware of re interns. We do have schools that try to push unpaid interns (I think they are afraid people won't pay) and we just say we only take paid interns. Our interns in high school start at $10 per hour and college start at $12. We do have interns who are given raises fairly soon in the internship because they prove themselves early on.

Interestingly, all must write. (EGOL). We had a computer science major just finishing freshman year at college and this was his first job. He is going to be excellent at Computer Science...he is a brilliant writer and he never knew it. Brilliant. I smile writing about him.

One of our interns walked into our VPs office and he had been given a task of designing wire frame and comp for a client once the KWA and sitemap were finished. I was sitting in the conference room next door when he said to the VP "I can't do this, this is not really my forte." Johnray paused a brief moment and said OK, I need you to understand something, this is business, we do not have an option to tell a client we cannot do something. I would appreciate you going back and finishing, and then he looked down at his work.

The intern nailed wire frame and design with little intervention, but he wanted to quit. This was not his area of expertise. Of course we look over all and our clients are protected with NDA and non competes, etc. But it's amazing to watch as the people realize they can do more than they ever dreamed. It is truly fulfilling.

To each of you I say Kudos. I would love a world that was open source, open education, and where interns were brought in to learn and thrive in an organization. We now have two interns in good positions who are no longer interns. One in web dev and the other in writing and social media.

Thanks to all of you,

Robert

xenu linksleuth is the answer to your question. Good luck. Nothing better I am aware of.

I was going to leave this lie and I already thumbed up Gianluca for his (as always) excellent response, but whenever I see the word spinning it bugs me. There was another question today re finding duplicate content on your own website. I went to copyscape.com and put in a portion of an article I had written about a drug in about October of 2010. I was looking to see if it showed up in two client websites as a blog posting. Imagine when I saw it in several other sites with poor grammar added and misused modifiers, etc.

So, the whole idea of using some crap spinning software and churning out anything in twenty different and bad permutations is the most counterproductive SEO tactic today. Then to submit it to clowns who are going to have links to you for a fee is the second most counterproductive.

Lastly, in SEO, when you have found the easy way to do something, generally, it is wrong or at best very temporary. Think about it, if it is easy every clown who professes SEO knowledge is doing it so there is no advantage. Those who truly work at SEO are the ones who succeed for themselves, their companies, and their clients. Write good content. Do the work to get good links. Then sit back and smile when you smoke these chumps.

Sorry for the rant. I had a moment