Not many people have one. Not many people have even heard of it. Alexey Stakhov (pictured here) has one. His web site says he is a Grand PhD in Computer Science, a Professor, and President of the International Club of the Golden Section.
The little-known, delightfully shadowy World Information Distributed University (WIDU) says: “To receive the degree of Grand PhD, it is necessary to have the degree of PhD of WIDU, to publish more than 100 scientific papers, 2-3 monographs, to take part in training of 10-20 PhD, to take part in solving of global problem as a supervisor. It requires 5-10 years.”
BONUS: Developer and Trainer David Grand, Ph.D., discoverer (so his we site informs us) of the Brainspotting profession, does not have a Grand Ph.D., except in the most technical sense.