It is etiquette that neither a brahmana nor a ksatriya king is ever insulted by the citizens; even though a king appears to be sinful, the citizens should not insult him
SB Canto 4
It is the duty of all citizens in a state never to insult the king, even though he sometimes appears to have done something very sinful. Because of his prowess, the king is always more influential than all other ruling chiefs.
According to Vedic civilization the king is supposed to be the representative of the Supreme Personality of Godhead. He is called nara-nārāyaṇa, indicating that Nārāyaṇa, the Supreme Personality of Godhead, appears in human society as the king. It is etiquette that neither a brāhmaṇa nor a kṣatriya king is ever insulted by the citizens; even though a king appears to be sinful, the citizens should not insult him. But in the case of Vena it appears that he was cursed by the nara-devatās; therefore, it was concluded that his sinful activities were very grievous.