Made infamous by corsairs and pirates most of which did not know they were they PsykWytches' loyal servants (and not always by choice) in the 17th and 18th century.
If someone gained the ire of a PsykWytch of the Black Spot Coven, their hands would be marked with a black spot on the palms which could never be removed or washed away. These spots usually signaled death unless they could possibly regain favor in the service of the Coven. The PsykWytches often created havoc with their Psyk-Magyiks powers, curses, and maligned influence to gain wealth to support their own greed and need for power.
...or were they actually stopping mere mortals from their own destruction?
There were good PsykWytches too.