The best Google can do is to remove said sites from their search results but that will certainly be a long process. Even then, these sites might still show up in yahoo, bing etc. Of course, the sites remain to exist in this case.
Your best bet may be to contact
WIPO - World Intellectual Property Organization if you haven't done so and see if there are any possibilities.
Another way might be to contact the registrar of the domainname of said malicious sites as these sites could be violating the registrars terms of use. Check
Domain Tools: Whois Lookup and Domain Suggestions