Does someone who calls themselves a libertarian, they automatically speak for all libertarians? Tell me, does Hillary Clinton speak for all Democrats? Does Ted Cruz speak for all Republicans? Does Bernie Sanders speak for all socialists?
Someone advocating the privatization of a police force is more likely an anarcho capitalist than a libertarian. Even a place like Sandy Springs, GA or Maywood, CA use government police forces: http://www.nytimes.com/2012/06/24/business/a-georgia-town-takes-the-peoples-business-private.html?_r=0