KKK can refer to several different organizations.It can refer to: 

Ku Klux Klan (sometimes called the Klu Klux Klan) which lynched African Americans predominantly in America's south during the Civil War Era up until the 1960's. Or...

Kataastaasang Kagalanggalangang Katipunan ng mga Anak ng Bayan, the largest revolutionary group that fought for the independence of the Philippines from Spain. Or...

Kuhnle Kopp Kausch, a German group of industrial firms.