I collect cone shells fairly often. On Sanibel, we have Alphabet, Dusky and Florida cones. I just watched a NOVA documentary on venomous creatures, and to my surprise learned ALL cone shells are poisonous!
According to several online resources, the neurotoxin of these Atlantic varieties are not as deadly as their Pacific kin. However if I do run across a live specimen, I will certainly handle with exceptional care while returning it to the sea.