UJM said:
“At the end of Shmiras HaLashon (Hilchos Rechilus 9:15), the Chofetz Chaim
writes that the prohibitions against Lashon Hara and Rechilus
do not apply to reshaim and kofrim and that it is,
in fact, a mitzvah to mock such persons:”
“It is a mitzvah to make their false opinions public before all,
and shame them so that others do not learn from their evil deeds.”
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MY RESPONSE:
[1] Most secular Jews in Israel today are Tinok SheNishba,
or close to Tinok SheNishba, so this does not apply to them.
[2] When Jews are under intense attack,
both in Eretz HaKodesh and in the Exile,
that is THE WRONG TIME for Jews to publicly attack each other.
In his Sefer HaMidot, Rabbi Nachman of Breslov ZTL ZYA taught that:
“When Jews are united, the Gentiles fear them.”
[3] While mocking heretics is taught by our Torah,
it should not be done at a time in history when
there is a danger of a Jewish Civil War (G*D forbid)
with Jews fighting and killing each other (G*D forbid).