Yep, after reading this thread, I went and looked and it seems I have somewhere north of a few hundred, dare I say close to a thousand. I am not seeing any aparent harm. Rather, I can see where my Calaustrea's have encrusted over a few. They seem to prefer the porcelain based Caribsea rock that everything else has avoided. They also appear to dominate the undersides of all the rock where corals would not grow anyway. Perhaps my tank has worked out a compromise. Time will tell.