Taken from www.briskodesh.org
Know that there are two sides.
The side of good, and the side of evil (Sitra Achrah).
G-d created evil to provide man with free will.
The Sitra Achrah is like a shell (klipah) it has no energy of its own.
All the klipas must receive their substance from the side of holiness (kedusha).
In the days of idol worship (avodah zarah) people would consciously channel energy to the forces of evil through meditating and other practices.
Human fluids especially, provide substance to demonic forces.
It is for this reason that many satanic rituals require semen or blood.
All pain and suffering that exists in the world comes from the klipas.
In this generation the klipas receive most of their nourishment from people who are pogem their bris (desecrate the convent).
The most common of these transgressions is spilling seed (motze zera lvtalah).
Unfortunately this sin is quite common today. If people would realize its consequences many would stop.
Due to our low level and many sins, this topic is ignored
Just the opposite, shmiras habris is the most important issue to deal with today.