Definition:
If someone infringes on your arts / crafts copyrighted material and doesn't respond to your email request to remediate the situation, your next step is to send a cease-and-desist letter.
The letter should include a brief description of the work being infringed upon, the url of such work and the url showing the copyright violation. If you have registered your copyright, include a copy of that as well.
This letter should be sent via USPS, UPS or FEDEX with a signature confirmation to the physical address associated with the offending link. If you can't find a physical mailing address for the copyright violator, fax the cease-and-desist letter and print a confirmation page. Lacking both avenues of contact, email the internet service provider (ISP) that hosts the infringing Web site.