I've never eaten at Joe's Crab Shack, but I know it's a popular place. I've seen the pictures of people wearing shirts that say "Peace, Love, Crabs" on them that come from the restaurant. But I find it the oddest thing to have on a shirt...
There is nothing peaceful about eating a crab. Nothing at all. And I'm assuming here that they are referring to the type of crab that people are eating in their restaurant, and not the pubic hair variety. Those eating crabs are killing an animal, when there is no threat or need to do so. We live in a country of abundance, so there are plenty of more "peaceful" food options available.
The definition of peace is a state of tranquility or harmony. How does one take the life of a crab and yet profess peace? It can't be done. The question is, do crabs feel pain, or do they suffer? The answer, according to a lot of research (and common sense), is a resounding yes (read about it here and here).
So I ask you, if you are intentionally harming another creature, who poses no threat to you, are you indeed displaying peace or love? I would say no, not at all, making the shirts a mockery of what peace and love really means. Remember, peace begins on your plate. Clever marketing by Joe's Crab Shack, but far removed from the reality of the situation.