Many people like emerald crabs. Some reefers I really respect like emerald crabs. I believe they are nasty predatory killing machines. But some people like them. They eat bubble algea, which is terrific. And they eat Gorgonians, so if you have a nusiance $100 sea fan named Fanny they will make sure you never have to use phyto again. Phyto can be expensive. And they are simply indispensable for performing quality control of your gluing skills. Every morning you will find out which specimens could be knocked over. It's a valuable service. An hmmm... Who doesn't like escargot? So you can't blame the for eating snails. I, myself, prefer them with garlic butter but the emerald crab is a purist. I know people who love emerald crabs. I know people who believe that Beanie Babies are still a good investment. I believe that emersld crabs drop grand pianos on kittens and replace all your compact fluorescent light bulbs with cheap incandescent 100 watt bulbs while you sleep. Some people really like them.