Palythoa heliodiscus: a photo of one of the more toxic types.
http://www.zoaid.com/gallery2/main.php?g2_itemId=2676
I cannot find a useable photo of palythoa toxica, but it seems to be another of the large polyp palys, looking similar to heliodiscus. I suggest you carefully copy the Latin names (always the most accurate) and look them up: familiarize yourself with them. Most zoas are mild, and collectors probably don't like to mess with these toxic types any more often than we do---but they can get included in with others, especially when small.
Unfortunately many zoa reefers are young folk, and may not have the background yet to read the science articles, but this is an area of the hobby where good handling practices are required.
As stated above, many marine species have defenses, and repeated exposure can make them into a hobby-ending problem. Gloves and glasses are such an easy precaution.
A few marine organisms have serious toxin, and toxin can be a life-altering if not life-ending problem. It's like keeping various sorts of animals: know what you're handling, and take appropriate precautions.
I would (my own opinion) urge anybody who thinks they do have one of the seriously toxic types, which they have identified, to remove it, dispose of it in a safe way, as you would dispose of an unwanted box of poison, and please not to trade it on. Our hobby has many safe ones. Let's not proliferate this problem.