Further to my recent success with having a pirated copy of my book removed from a forum site, several people have asked how I found the IP address and subsequently the host of the site in question.
Firstly, I advise everyone to follow regular protocol: send a standard DMCA notification with a specified time limit for a response. Most sites will respond to those notifications without you needing to take the matter further. However, if you don't get any joy from that, here's what you do next.
Make sure that your book is being pirated.
Seems like a no-brainer, right? But you'd be surprised how many indies I've seen getting themselves in a flap over phishing sites that don't actually have their book at all. There's an easy enough way to test this: type a random string into the site search field. Just hit the keyboard - rgksl ergrbns vwegosvs will do nicely. Then search for it. If the site shows a positive result you know that they're claiming to have anything that people search for, just to get you to sign up / download their virus, whatever. Other good checks are if they're showing that they've got your book in mobi, mp3 and wav. Basically if they're showing file types that aren't relevant and you know your book doesn't exist in. Finally if you're still not sure then do a limited search, e.g. if you're searching by your author name and it comes up with 101 results for your name only, stop stressing, but if they come up with files that are your author name and your title and all the right details, panic.
Find the owner.
This is the person who has bought / leased the site, and who is responsible for its content. Go to http://www.whois.com/ and search for the site name. That will either give you the real name, street address (don't egg their house!), phone number and email address of the owner, or the details of a third party whois blocker. A lot of site owners go through these third parties just because they don't want all their personal details spread across the net, it's not necessarily sinister. Either contact the owner directly, or contact the third party, who will pass on your message to the owner. If that doesn't work...
Get the IP address.
Every site has one of these, it's like the telephone number for the website. E.g. Google's IP address is 188.8.131.52. There's an easy way to find this from your computer, just go to Start >> All Programs >> Accessories >> Command Prompt then in the black box that opens type "ping" and the website you're searching for the IP for (so for google type in "ping www.google.com") (without the "inverted commas") and press enter. You'll get a response that says "Reply from" and then a series of numbers like the Google one I just showed: that's the IP address. Failing that there are loads of websites that will trace an IP - just Google it.
Find the coordination centre.
Once you've got the IP address you can go to http://www.arin.net/ and in the very top right you'll see "Search Whois" and a box - enter the IP address in there. That will tell you what regional coordination centre is responsible for the IP, and you should be able to find their website (or alternatively google their name to find it if you're struggling).
Find the host.
Go to the site of the coordination centre and they should have a function to search their database. Stick the IP into that search engine and that should bring up all the details of the host of the site. The host is the company who can ultimately pull the plug on the whole site. They don't necessarily own the site or hold any responsibility for the content, but they can and will issue ultimatums to the people who do. Always be polite when contacting the host - they are your best resort for swift action, but remember that they are not necessarily directly responsible for your work being pirated, and likely have no idea it is happening and do not want to be associated with it where it is. I cannot stress this enough - don't piss them off. These people can pull the whole site if they want. Drop them a line with the IP address of the site and the link to the actual page with your book on it, and they should be able to help you.
In the meantime...
Getting pirated content taken down can take time, even with the best efforts of the people you're working with. While you're waiting for that to happen, consider guerrilla techniques. When my book was pirated on a forum I joined and left a post, politely explaining who I was, and how it damaged me when my book was pirated. Treat the people sharing the file as fans - after all, they like your work enough to want it, even if not enough to pay for it! - be polite but make the point that you're unhappy at what is happening. A lot of people see filesharing as a victimless crime, they think they're getting one over on the big corporations that can afford the loss. Explain to them that this is not the case, and that you feel the loss of every single sale. Perhaps encourage people who have already helped themselves to leave you a review somewhere. It can't hurt, right? And if you twinge even one person's conscience, you're helping not only yourself but other ripped off indies out there.