I believe I got this here a while back, some good advice. Hope it works for you:
Don't shy away from legal action... if you do, they will smell it and never stop their illegal behavior. Copyright holders win nearly 100% of the time in court in these cases.
First, DOCUMENT the infringement. Get someone else to view, print, and document the infringement... use a video camera too.
Second, send a DMCA "take down" notice to the upstream provider. Get the IP address of the server, go to http://www.network-tools.com
and do a traceback to get the domain of the next hop upstream from them. Here is the notice I use:
Dear Abuse Department:
I am writing this letter as the holder of rights under copyright of images that have been, without authorization, published on the web site "www.#########.com."
No one is authorized to publish, exhibit, reproduce, transmit, or otherwise distribute the above-mentioned work(s) without my express written permission, which permission I have not granted to "www.#######.com" or ####### Telecom, Inc.
The attached documentation illustrates a portion of my images as displayed on the "www.#######.com" website.
The distribution of unauthorized copies of copyrighted images constitutes copyright infringement under the Copyright Act, Title 17 United States Code Section 106(3). This conduct may also violate the laws of other countries, international law, and/or treaty obligations.
Since you own this IP address, I request that you immediately do the following:
1) Disable access to the copyrighted images identified above and;
2) Fully identify all persons and businesses known to you to be the holders of that account.
3) Retain all records, logs, and correspondence related to the domain "www.#######.com" for future legal action.
As the exclusive rights to the copyrighted material at issue in this notice, I hereby state, pursuant to the Digital Millennium Copyright Act, Title 17 United States Code Section 512, that
I have a good faith belief that use of the material in the manner complained of is not authorized by me or the law.
Also pursuant to the Digital Millennium Copyright Act, I hereby state that we believe the information in this notification is accurate, and, under penalty of perjury, that I am the owner of the exclusive rights being infringed as set forth in this notification.
Please contact me at the above listed address or by replying to this email should you have any questions.
I appreciate your assistance and thank you for your cooperation in this matter.
Third, if the Whois information is bogus, report it to:
Wait a few days... their entire domain may go [poof].
Finally, if you have NOT YET registered copyrights on the images, DO SO IMMEDIATELY.