There is not a lot of recourse against the site itself, especially if the site is out of the country. If the web hosting site is U.S.A., you can send a DMCA take down letter to the web hosting site. 263 more words
Thank you to S.K. Nicholls for sharing this information.
In cases of copyright infringement, contact the site's hosting company rather than engaging with the offending site. The following advice is particularly useful in finding out if your work is being pirated: "One thing you can do to help protect yourself is set up a Google alert with your book title(s) and author name." The information provided in her post is for reporting American sites to their hosting company.
As of January 1, 2015, Canadian internet service providers will be required by law to notify their customers of copyright infringement. (See article in The Huffington Post Canada.)