What is the authority of HKM?
When we want get material knowledge like physics,chemistry, mathematics and computer languages like C, C++ etc. we look for authorized institutes. But when it comes to spiritual knowledge we tend to invent our own understanding about spirituality. But, the fact is that there are authorized institutes (sampradaya) for spiritual knowledge as well.
In the Padma-Purana, it is mentioned that
The meaning is that in the Kali-Yuga four Vaiñëava sampradäyas—Çré, Brähma, Rudra, and Kumära—purify the earth.” The disciplic succession from Lord Brahmä is called the Brahma-sampradäya, the succession from Lord Çiva (Çambhu) is called the Rudra-sampradäya, the one from the goddess of fortune, Lakñméjé, is called the Çré-sampradäya, and the one from the Kumäras is called the Kumära-sampradäya. Of these, the Brahma-sampradäya is the oldest. All of the four original sampradäyas are still scrupulously engaged in the transcendental service of the Lord up to date, and they all declare that Lord Kåñëa, Mukunda, is the Supreme Personality of Godhead, and no other personality is equal to Him or greater than Him. One must take shelter of one of these four sampradäyas in order to understand the most confidential religious system.
Hare Krishna Movement belongs to Brahma-Sampradaya and His Divine Grace A.C. Bhaktivedanta Swami Prabhupada, Founder-Acarya of worldwide Hare Krishna Movement, is the 32nd Spiritual Master coming in Brahma-Madhva-Gaudiya Sampradaya, an unbroken chain of disciplic succession.