Cactus experts say there are about 2,000 different types of cacti living today. Many of them are out here in the deserts of the West, but they’re in danger. According to a study published last year in the journal “Nature Plants,” almost one third of them are threatened with extinction. They’re threatened by humans taking their habitat, and livestock trampling them. The biggest reason so many cacti are disappearing, however, is a simpler one: theft. People are stealing rare breeds and selling them. There are laws against it, but they’re tough to enforce across hundreds of thousands of square miles of the desert West. We take a look inside the cactus smuggling trade.