If they refuse to pay or take down the content after you first contact them or send a C&D letter you can also contact their hosting company. If you can prove that you own the rights to the content and that the site is infringing, the hosting company will probably take down the site and/or terminate the person's account.
Here's the info for filing a DMCA (Digital Millennium Copyright Act) complaint with Google : http://www.google.com/dmca.html
CopyScape.com is a website, that allows one to verify the uniqueness of the content. If your article, passes the CopyScape test, your article can be assumed to be "Unique".
Just buy premium account and they give you 200 chance in $10
Normally 4-7% copy is fine..no problem..
Because copyscape shows the matches all from net...so if you make article on any celebrity than his/her name and all biography will be same ..so 4-7% is obvious..
Don't worry about that.,,
Mostly above 24% copy google reject you..below that not to worry.....go through it..