SB 1.18.6
yasminn ahani yarhy eva
bhagavan utsasarja gam
tadaivehanuvrtto ’sav
adharma-prabhavah kalih
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The very day and moment the Personality of Godhead, Lord Sri Krsna, left this earth, the personality of Kali, who promotes all kinds of irreligious activities, came into this world.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The Personality of Godhead and His holy name, qualities, etc., are all identical. The personality of Kali was not able to enter the jurisdiction of the earth due to the presence of the Personality of Godhead. And similarly if there is an arrangement for the constant chanting of the holy names, qualities, etc., of the Supreme Personality of Godhead, there is no chance at all for the personality of Kali to enter. That is the technique of driving away the personality of Kali from the world. In modernized human society there are great advancements of material science, and they have invented the radio to distribute sound in the air. So instead of vibrating some nuisance sound for sense enjoyment, if the state arranges to distribute transcendental sound by resounding the holy name, fame and activities of the Lord, as they are authorized in the Bhagavad-gita or Srimad-Bhagavatam, then a favorable condition will be created, the principles of religion in the world will be reestablished, and thus the executive heads, who are so anxious to drive away corruption from the world, will be successful. Nothing is bad if properly used for the service of the Lord.