I would suggest a search on this site for "emerald crab" and count the number who've never had a problem (I have seen three people say that) and then count those who growled and struggled to catch their little coral killer (happened to me and I've lost count how many others). Essentially, it's like Russian roulette, except in this game, only one chamber is empty.
You may beat the odds and never have a problem. But I wouldn't bet on it. I've removed two for eating coral, and there was no shortage of other food available.
Someone stop me! Please! But... not just yet...
55 Gal Tropical FW
55 Gal Mixed Reef