(from Sri Bhaktisiddhanta Vaibhava vol. II, p. 154-155, HH Bhaktivikash Swami)
Yet leaders of apa-sampradayas being loath to broach these topics, the very term namaparadha was virtually unknown until Srila Sarasvati Thakura enunciated the difference between offensive and pure chanting. So although Bengal reverberated with the names Krishna, Rama, and Hari, no one was becoming purified by that offense-ridden chanting. Contrarily, the sinful propensities of such offensive chanters often exceeded that of persons with no claim to piety. Hence Srila Sarasvati Thakura ruefully referred to prakrita-sahajiyas' chanting as being like that of parrots or a gramophone.
"Can kirtan really be considered genuine if some worthless people without any ardor for Hari-seva come together and howl? True Hari-sankirtan is that of genuine devotees, who serve Hari according to the principles enjoined in the Vedas and allied sastras. Kirtana is not Hari-sankirtan if conducted for the prevention of cholera or pox epidemics, for prosperity in trade, or for labha-puja-pratistha. Such kirtana is rnaya-kirtan.
"As long as we remain aloof from kirtana conducted by those who hold perfect Krsna-kirtan, maya will delude us in various ways. We will derive no benefit by joining the kirtan of persons not anxious for their own wellbeing, who hoodwink themselves. There will be no sankirtan if we follow such people who, without receiving instructions from true Vaisnavas, imitatively decorate their body with beads and tilaka and screech out some names that merely resemble harinam.
"The holy name is never revealed to one in the bodily conception of life, who thinks in terms of "I" and "mine."' Making a pretense of harinam, people are waltzing their way to hell.
Nevertheless, most putative Vaisnavas were unaware of their wrongdoing and were astonished by Bhaktisiddhanta Sarasvatis's expose of it. They had been raised with the misconception that Caitanya Mahaprabhu and Nityananda Prabhu were so merciful and the holy name so powerful that devotees are automatically exempt from scriptural injunctions delineating moral codes and gradual spiritual upliftment. On hearing him describe namaparadhas, surprised listeners would wonder why they had never previously received these important instructions, whereupon Srila Bhaktisiddhanta Sarasvati would clarify that it was the duty of a guru not only to give the name of Krsna to his disciple, but to inform him of and instruct him to stop committing the ten namaparadhas.