The Hafada piercing is a scrotum piercing on the side of the scrotum, where there
is a crease. It is supposed to have originated in Arabia and spread through Northern
Africa and the Middle East. The piercing is carried out as a puberty ritual, it
is generally done on the left hand side. The piercing was supposedly bought back
to Europe by French Foriegn Legionares when they were stationed in what is now
Lebanon and Syria.
Scrotum piercings aren't practised by any primitive tribes, at least I can't
find any evidence of such practices, it's really a modern western invention.
Some people have an incredible number of piercings through their scrotum, Sailor
Sid one of the early piercers had 120 scrotum piercings at the time of his death,
and he planned to have more.