Don't write a web spider to search for the names of authors you "represent."

Don't send the website owners an email saying that everything it finds infringes on their copyrights.

Don't send the website owners another email telling them that list is a DMCA takedown notice.

Don't bother to vet your request to ensure it only includes works that are infringing on your clients' copyrights.

Don't include a high-quality eZine that chooses to distribute itself online through that website in your list (go back to the list and search for "Ray Gun Revival")

In particular, don't include a Creative Commons-licensed work by a writer who thinks the DMCA is insane on your list because one of those names is mentioned in a cover blurb (go back to the list and search for "Down and Out in the Magic Kingdom").

(And yeah, if you're the service provider or webmaster and you get a "take down notice" don't just take down the stuff before confirming that the request follows the standard for a takedown notice, and if it doesn't ask the person to re-submit a notice that does.)