if we are talking about zoos, yes they can be dangerous if you just handle with your hands and more if you try fragging them.
i don't think yellow polyps, green star polyps are dangerous or at least i have never use globes to move them around, but i think no matter what you are moving around the tank, it's always good to use globes because you never know and i think it hurts less to move rocks around than when you are not using globes, just my opinion dood.