What is the ruling on shaming a man who toys with girls' emotions and laughs at them on YouTube?

If a man deceives women and uses honeyed words to win them over, this is a great door to evil and corruption. He is disobedient and engaged in fitna (temptation/strife). Therefore, it is permissible to expose him for what he has disobeyed Allah in, because his harm extends to others, and this is considered advice (naseeha) to Muslims.

However, the warning must be limited to what is necessary, such such as exposing him within his sphere of influence or to the individuals he targets, without extending beyond them. This is because the default is the sanctity of a Muslim's honor, and one does not deviate from this principle except out of a necessity that is estimated according to its extent. Exposing him on YouTube might exceed the necessity and the benefit.