The rhinos are killed for their horns, which mostly end up in Vietnam and China, where they are valued for their supposed medicinal value. Research shows that they have none, however, and that they are made up of the same material as human fingernails. Most of the animals were killed in Kruger National Park. A total of 343 alleged poachers and traffickers were arrested in 2013, an increase from 267 arrests in 2012. But that's clearly not getting the job done.