You need to call upon the UDCP when you have a domain name dispute. All registrars in the .biz,.com, .info, .name, .net, and .org top-level domains follow the Uniform Domain Name Dispute Resolution Policy (UDCP).
Registrars typically will not do anything unless there is a court action or arbitration, particularly if there are trademark issues.
If you have an issue you are probably looking to have a domain canceled, suspended, or transfer a domain name.
So what do you do? Well if you are a Trademark holder you can (a) file a complaint in a court of proper jurisdiction against the domain-name holder (or where appropriate an in-rem action concerning the domain name) or (b) in cases of abusive registration submit a complaint to an approved dispute-resolution service provider.
Find more here.