Joe – You would shout, but you wouldn’t hit to stop somebody talking Loshon Horo/wearing something immodest?
The Gemara Kesuvos 86a writes that you can use lethal force (According to the Meshovav Si. 3, Chasam Sofer OC #177, Ramba”m on Mishna 48b. Igros Moshe disagrees partially) to enforce the performance of a mitzvah. The Gemara proceeds to differentiate between positive commandments and negative commandments, although what the distinction actually is is not clear.
R’ Akiva Eiger asks that the law is that you can use physical force to enforce negative commandments too. The Ketzos HaChoshen (Meshovev #3) differentiates between positive and negative commandments in regards to to the allowance for lethal force, and only non-lethal force is allowed for negative commandments.
So – Joseph – would you use force?