Well not those zoanthids...at least I don't think.
I believe you are referring to palytoxin, which is produced from a few species of corals, but it's mostly zoanthids in the Palythoa genus. However, there are also reports of Parazoanthus species producing it. And I believe that some of the organisms that produce it aren't related to zoanthids at all!
Either way, I'd avoid touching them if you have an open wound. Zoanthids are one of the cheapest and most-common corals on the market, with many stores offering frags starting at $5-10. And it's true, poisonous ones make it into the trade on a regular basis.