Recently I was made aware of a file sharing site that reportedly had digital copies of published books, as well as music and other copyright content. I had a look for myself, and found this to be true.
The site, 4shared.com, has thousands – maybe tens of thousands – of copyrighted books, music, and other content, freely online and available for anyone who wants to browse the site and download content.
Readers: it is illegal to post copyright content in any form online, unless you are the legal owner of the content or have written permission from the owner. It is against the law. Do not be deceived by the lure of free content.
Professionals: if you are found to be in possession of illegally copied protected content, you may be in jeopardy of losing your professional licenses or certifications. You can also be sued by the copyright owner.
4shared.com will remove content on request. It is necessary to state, in detail, who the owner of each item is, and why it should be removed. Digital copies of many of my books were on the site, and I filed removal requests for each. Yes, it was time consuming. To request illegal content be removed, send an e-mail (with the full URL of the offending item(s)) to abuse@4shared.com, or visit http://www.4shared.com/contact.jsp , click on the “Copyrighted Materials” link, and complete the short form there.
The extent of illegal content on 4shared.com is appalling – it is a cesspool of of illegal content. A quick search showed that almost one-thousand “For Dummies” titles were on the site.
Peter H. Gregory 
Yes, that is correct. There are several file sharing websites on the internet. Part of my job, as your business manager, was to discover whether any of your published works had been made available this way, and indeed they had.
It is my understanding that file sharing itself is a legal technology with legitimate uses, however most people are obviously uploading and downloading files containing copyrighted materials without permission or authorization, which makes it copyright infringement. The problem is that most of the file sharing sites have very cleverly hidden their original uploading source so prosecuting becomes more complicated.
You will be happy to know that your books are no longer available on 4shared.com, so apparently, it does pay to file a request for removal, as you did.