All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Slandering a Muslim individual and accusing him of committing Zina is one of the grave major sins. It was narrated that the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, said: “Avoid the seven sins that doom a person to Hell.” It was said: "What are they, O Messenger of Allaah?" He, sallallaahu ‘alayhi wa sallam, said: “Associating others with Allaah in worship; sorcery; killing a soul that is forbidden to be killed, except in cases dictated by Islamic law; consuming Riba (interest); consuming orphans’ wealth; fleeing from the battlefield; and slandering chaste, believing women who are unaware of the accusation cast upon them.” [Al-Bukhari, Muslim, and others]
Whoever slanders an innocent Muslim has indeed deserved the corporal punishment of slander, which is eighty lashes. Allaah Almighty says (what means): {And those who accuse chaste women and then do not produce four witnesses—lash them with eighty lashes and do not accept from them testimony ever after. And those are the defiantly disobedient, except for those who repent thereafter and reform, for indeed, Allaah is Forgiving and Merciful.} [Quran 24: 4-5] This is so whether the accusation was against a man or woman, explicit or implicit, according to the most preponderant opinion of the scholars.
Imaam Maalik said in Al-Muwatta’ that a man slandered another, as he said: "By Allaah, my father is not an adulterer and my mother is not an adulteress." ‘Umar ibn Al-Khattaab asked the companions' advice about the indication of that statement. One of them said, "The man has just praised his father and mother." Another said, "He could have praised his father and mother in a way other than that. We think that he is to be flogged according to the prescribed corporal punishment." So ‘Umar lashed him eighty lashes as a corporal punishment.”
Casting an accusation of Zina through mass media is even more prohibited and constitutes more slandering and scandalizing for the accused. Thus, discretionary punishment should be carried out against whoever does so because it is a form of spreading immorality in the Muslim society.
Allaah Knows best.