It should be illegal everywhere but there are some states/cities/countys that have banned the practice. The chicks aren't harmed by the dying itself, it's just that often times people will buy them as a sort of holiday toy for the kids. No food, maybe some water. I met a lady who works in our headquarters office and she said her family would buy a few for her and her brother every Easter 'but they never lasted long'. Guess no one in the family could figure out what to properly feed them and no one cared enough to find out. So every Easter this family essentially bought two or three chicks for fun and then just let them die right in front of the kids. Every year. The view was kinda like they were toys that would run down and break after a few days. Just a given.
Yes, some people just do it as something cute to do and are perfectly responcible with the chicks as they grow. But people like the ladies family (who, I might add, expressed NO regret; either for herself or for her families actions) are the perfect example as to why this should be illegal across the board.