It may very well be "reef safe" in the sense that it won't eat anything but algae. That said, I am sure it would be quite the bulldozer. Not knowing the exact species, I have had some larger turbo snails that are "reef safe" that would plow through frag setups... much to my chagrin. I now remove them as they get big and are more clumsy. Unless you have a HUGE tank and algae growing like a carpet, not sure that thing would be good in a reef.
In the basket in the bottom left of the picture, he has at least 3 more. I suspect he is catching these things from te ocean and trying to sell them. Most likely without a permit. Most likely illegally.