Some people are allergic to anemone stings, and will get quite a bad rash! I've been "Stung" many times and it's nothing more than a sticky feeling. I would still wear gloves when handling a carpet, as different people all have different reactions to the nemotocysts.
My LFS owner had quite a reaction to a carpet anemone sting. He had to go to the emergency room becuase his whole arm swelled.
Graham