Well, a quick check and the sites that tend to infringe on me are still operating.
I can take down an "offending website" by sending a letter to a webhost and Google (DMCA).
Sure does, however imagine a content site with 20,000 documents (like mine) and envision how much time and effort is takes to submit these DMCA's. It is a constant battle for me and I really wish I could spend my time doing other more productive stuff other than chasing copyright infringers.
BTW, the sites that accept user submitted content are the ones causing me most of my challenges right now. Visitors are converting my webpage's to PDF's and republishing.