I could find no evidence of any Phaidriades-related executions of any sort. The only source I could find that mentions people falling off the cliff is the "Griechenlandbuch", which mentions that men, wracked with guilt over something or other, would jump to their deaths. The book is an even more interesting story: two German soldiers were assigned to wander, basically as unarmed tourists, through conquered Greece in 1942, writing and drawing of their adventures. Their prose and sketches were then turned into a book that the commander of the Southwest European Air Command gave to all his soldiers for Christmas.

Chris